Xo 4 User manual

XO 4 & XO FLEX
TROUBLE SHOOTING GUIDE
YB-907

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 2
CONTENTS
No “welcome” message on display. No light on the main switch (early model) ................... 10
No light in the display ............................................................................................................10
“NETWORK FAIL !!” “CALL SERVICE”.....................................................................11
“FOOT CONTROL FAIL” “CALL SERVICE”..................................................................... 11
“POWER DRIVER FAIL!!” “CALL SERVICE”..................................................................... 12
“STAND CONTROL FAIL !!” “CALL SERVICE” ....................................................................12
“WATER LEAK” “CALL SERVICE” .................................................................... 12
“UNIT NOT READY” ..............................................................................................................12
“NO WATER FLOW”..............................................................................................................13
“CHAIR SYNC FAILED” .........................................................................................................13
“CODE BLOCK REQUIRED” “CALL SERVICE” ...................................................................13
“CS ERROR” .........................................................................................................................13
“MISSING DMX PCB”............................................................................................................13
“WRONG INSTRUMENT” ......................................................................................................13
“WRONG SUSP PCB”...........................................................................................................14
“CHECK WHITE BOTTLE”.....................................................................................................14
“CHECK YELLOW BOTTLE”..................................................................................................14
“SUCTION CLEAN FAIL” “CALL SERVICE”.......................................................................14
LED D3 is off (Power supply chair).........................................................................................15
LED D2 is off..........................................................................................................................15
LED D1 is off (transformer and power supply) ......................................................................15
LED D1 and D3 are OFF ........................................................................................................15
D1 LED is OFF (24VAC) .........................................................................................................16
D2 LED is OFF ±34VDC.........................................................................................................16
D3 LED is OFF ±34VDC.........................................................................................................16
D6 LED is OFF 5V, 12V, 24VDC.............................................................................................16
All LEDs on the “Power supply PCB” are OFF and LED’s on “Mains PCB” are ON.............. 16
Precision voltage measurement:............................................................................................16
Procedure: ................................................................................................................................17
Cause:.......................................................................................................................................18

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 3
Control Pedal.........................................................................................................................18
XO Operating light .................................................................................................................18
Joystick Base chair................................................................................................................18
“Water Clean” and “Suction Clean” system........................................................................... 18
“BACKPLANE”– 5V Connections ..............................................................................................18
D29 LED is OFF (24VDC) .......................................................................................................20
Chair .........................................................................................................................................21
Failure description .................................................................................................................21
The chair does not work properly (Lifting or lowering) ...........................................................21
Chair synchronize fails...........................................................................................................21
Liquid sensors...........................................................................................................................21
Liquid sensors do not work ...................................................................................................21
Valves (air & water)....................................................................................................................21
Valves in unit stand do not work..........................................................................................21
OP Light ....................................................................................................................................21
The OP Light does not work ..................................................................................................21
Joystick Base (Chair position) ...................................................................................................21
Base joystick does not work..................................................................................................21
Water Disinfection system.........................................................................................................21
Water disinfection system does not work properly. ...............................................................21
Suction disinfection system ......................................................................................................21
Suction disinfection system does not work properly .............................................................21
Purpose:....................................................................................................................................22
D800 LED is OFF (24VAC) .....................................................................................................22
D191 LED is OFF (24VDC) .....................................................................................................22
D110 LED, 3.3V is OFF (3.3VDC is generated from 5VDC on the Bridge PCB)...................... 22
Purpose:....................................................................................................................................25
D6 LED is OFF. ......................................................................................................................25
Purpose:....................................................................................................................................26
No water on instruments........................................................................................................26

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 4
Purpose:....................................................................................................................................27
Water arrives on the syringe but not distributed on the other instruments............................. 27
It is not possible to adjust the flow rate on the instruments................................................... 27
Point of measurement: ..........................................................................................................27
LED D110 remains OFF when the instrument is pulled forward........................................... 28
Wrong instrument. .................................................................................................................28
Wrong Susp. PCB. ................................................................................................................28
Information: ...........................................................................................................................29
Voltage measurement on the suspension PCB connector (CA-100, CA-101...)..................... 29
SYRINGE:..................................................................................................................................32
BLOCK SYRINGE, AN-510 :......................................................................................................33
No water or air on the syringe block ......................................................................................33
No spray air on the syringe module .......................................................................................33
SYRINGE 3F / 6F...................................................................................................................34
Failure description .................................................................................................................34
Syringe not activated when the suspension is pulled ............................................................34
Syringe activated when not pulled.........................................................................................34
No Water ...............................................................................................................................34
No air.....................................................................................................................................34
SYRINGE 6F..........................................................................................................................35
No hot water/air.....................................................................................................................35
MICROMOTOR MC3 BIEN AIR .................................................................................................36
Micromotor not activated when the suspension is pulled......................................................37
Micromotor is active while the suspension cord is not pulled................................................37
The motor does not run when the pedal is activated .............................................................37
No light ..................................................................................................................................38
No Water ...............................................................................................................................38
No air spray ...........................................................................................................................39
No “cool air” ..........................................................................................................................39
MICROMOTOR MX2 BIEN AIR..................................................................................................40
Specific error connected with Micromotor type MX2............................................................. 41
The motor does not run when the pedal is activated .............................................................41

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 5
“Missing DMX PCB” ..............................................................................................................41
TURBINE...................................................................................................................................42
The turbine is not activated when the suspension is pulled................................................... 43
The turbine is active while the suspension cord is not pulled ................................................ 43
The turbine does not run when the pedal is activated ...........................................................43
No light. .................................................................................................................................44
No water................................................................................................................................44
No air spray ...........................................................................................................................45
SCALER ....................................................................................................................................46
The scaler is not activated when the suspension is pulled .................................................... 46
The scaler is active while the suspension cord is not pulled..................................................47
The scaler does not run when the pedal is activated............................................................. 47
No water................................................................................................................................48
LIGHT CURING SYSTEM – LYSTA 88 / 89 & ODONTOCURE................................................... 49
Light curing lamp does not work when activated ..................................................................49
DÜRR CAMERA / VIDEO iX, iX HD, HD Smart: .........................................................................50
The camera does not work when the suspension is activated...............................................50
The camera is active when the suspension is at rest............................................................. 51
No Light.................................................................................................................................51
Image cloudy, Milky...............................................................................................................52
Image too dark ......................................................................................................................52
No image ...............................................................................................................................52
The camera vibrates when pressing the trigger button, but no picture is displayed .............. 52
Moving image judders ...........................................................................................................52
The image is blurred ..............................................................................................................53
Camera not detected by the software ...................................................................................53
Camera is not correctly detected when PC runs Windows 7................................................. 53
Camera is recognized as Vistacam IX HD without the interchangeable head ........................ 53
The trigger function is not working ........................................................................................53
Interchangeable head not engaging ...................................................................................... 53
Test cable for Dürr Vistacam .................................................................................................53
“Basic configuration”.............................................................................................................55
“Suction Clean System” ........................................................................................................55
“Water treatment”..................................................................................................................55
“Backflow prevention”...........................................................................................................55

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 6
“WATER LEAK!!” “CALL SERVICE”....................................................................56
Water pressure failure on the instrument bridge....................................................................56
Air pressure failure on the instrument bridge. ........................................................................ 56
Fault in air pressure to instrument bridge ..............................................................................57
No Flush or Rinse......................................................................................................................57
No cup filling. ............................................................................................................................57
The liquid detection sensor pins do not work properly. ......................................................... 59
Lower LED off (Mixing cup filled) ...........................................................................................59
Upper LED remains off when water reaches the short liquid detector sensor probes............ 59
Information: ...........................................................................................................................59
Water clean mixing cup is detected as empty when the cup is filled..................................... 60
The "Water Clean" dispenser detected as "low" when full (white bottle). .............................. 61
The liquid in the bottle does not circulate ..............................................................................61
Information: ...........................................................................................................................61
AN-374 Level Sensor PCB.....................................................................................................61
No water in the container.......................................................................................................62
Overflow (mixing Cup). ..........................................................................................................63
Air bubbles “shoots” water out of mixing cup........................................................................ 63
Valves & contacts connections in the "Basic configuration" and "suction cleaning". ............ 65
Overflow (mixing cup) ............................................................................................................65
The Mixing cup is detected as empty when filled ..................................................................66
The suction cleaning liquid is detected as "low" while the bottle is full (Yellow bottle) .......... 66
Unpleasant smells from the suction.......................................................................................66
Suction does not start when one of the suction hoses is lifted but suction motor starts. ...... 69
Suction starts when the unit is switched on...........................................................................69
No suction: (Valves activated / spittoon valve / CAS1 / Amalgam separator activated)......... 69
Connection Diagram..............................................................................................................69
The chair does not run properly (hacking while moving)........................................................ 70
No movement of the chair when the joystick or control pedal is activated. ........................... 70
The backrest motor does not work........................................................................................71
The backrest motor locks up when going up.........................................................................71

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 7
Major Cases: .........................................................................................................................71
Signal Measurement: Rectangular shaped signal ..................................................................71
Special Case: The backrest motor does not stop when reaching topmost position................. 72
Out of synchronisation...........................................................................................................72
Electrical Safety Tips .............................................................................................................72
Electrical work procedure:.........................................................................................................72
Reversal of the motor polarities. ............................................................................................72
Before proceeding:................................................................................................................73
Handling: ...............................................................................................................................73
Advice:...................................................................................................................................73
Synchronization:....................................................................................................................73
Mechanical work procedure:.....................................................................................................74
Disassembling of the drive bearer: ........................................................................................74
Powering up the Unit: ............................................................................................................74
Advice:...................................................................................................................................74
Chair synchronisation:...............................................................................................................75
To synchronise the chair, proceed as follows:.......................................................................75
Note that this description refers to firmware version 1.51 or later.......................................... 75
Alternative procedure: ...........................................................................................................75
Information ............................................................................................................................76
The XO operating lamp does not switch when it reaches working position 1 or 2................. 77
The OP lamp does not switch on when placing the hand under the sensor. ......................... 77
The OP lamp LED shines faintly.............................................................................................77
How to measure voltage output on OP light? ........................................................................ 77
Display shows « Foot control Error” during start-up ..............................................................78
“Network Fail!! “Call Service”.................................................................................................78
Nothing happens when the pedal is activated. ...................................................................... 79
No picture on the screen. ......................................................................................................80
Image quality problem ...........................................................................................................81
Screen problem. ....................................................................................................................81
Advisory.................................................................................................................................81
Spittoon Valves DÜRR...........................................................................................................82
CAS 1 DÜRR .........................................................................................................................82

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 8
COMBI-SEPAMATIC CS 1.....................................................................................................82
Spittoon valve is not working.................................................................................................83
Suction unit does not start or run continuously. .................................................................... 83
The liquid does not flow through ...........................................................................................83
CAS1 is not operational (display module off) ......................................................................... 85
The yellow and green LEDs are lit, and a melody is emitted.................................................. 85
The yellow LED is on, the red LED flashes and an acoustic signal is emitted........................ 85
The green and red LEDs flash alternately, and the acoustic signal is emitted........................ 85
The orange light flashes, and the acoustic signal is emitted..................................................85
The water is not drain properly from the cuspidor .................................................................85
Suction power is too weak or interrupted.............................................................................. 85
Device is running continuously ..............................................................................................86
Device is generating high vibrations ......................................................................................86
Water is not drained out properly ..........................................................................................86
CS1 does not start.................................................................................................................87
Suction line too weak or interrupted. .....................................................................................87

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 9
FOREWORD
This XO4 and XO Flex Unit Maintenance, Diagnostics and Troubleshooting Manual contains
detailed procedures:
- Schematic diagrams illustrating PCBs, sensors, instruments etc. and their locations.
- Information about PCBs, sensors, instruments etc. functionalities and their use.
- Description on how to remove and replace a part in the unit (Reference numbers are also
mentioned.
- Information concerning specific measuring points in the unit (Voltage, Ampere. Frequency etc.).
This manual also includes information on how to operate and maintain the unit.
It is intended only for qualified and XO-certified technicians who have completed and received
technical training, are experienced in troubleshooting and equipment replacement.
If you are in doubt about any of the procedures described in this manual, contact your XO
technician.
Some minor hardware and software failures involve troubleshooting techniques beyond the scope
of this document. Qualified technicians trained in troubleshooting will be better able to resolve
them. Your XO Technician can provide this type of service.
Related Documentation
The following documents are available online at the address below:
https://www.xo-care.com/technical-service/
DANGER!
Failure to observe the instructions contained in this troubleshooting guide could
result in personal injury and property damage and may void the warranty.
Read this troubleshooting guide carefully before servicing and testing the Unit.
If you do not understand the instructions described in this troubleshooting guide,
contact an XO technician.
Unit XO4 and XO Flex must be serviced in accordance with the instructions in this
troubleshooting manual.

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 10
START UP
Failure description
Reason
Solution
No “welcome” message on
display.
No light on the main switch
(early model)
Main switch OFF
Activate the main switch
Main switch ON
Check LED D1 and D3 on Mains
PCB are “ON”
Check the mains supply voltage
at J4 on Mains PCB, 230VAC.
Replace fuse(s) on the Mains
PCB if necessary.
Check the mains switch.
No light in the display
If the unit is ON and the Mains
fuses are ok
After removing the instrument
bridge top cover, check the
following
Check that diodes D800, D191
and D110 at Bridge PCB are ON.
If LED D110 (3.3VDC) is ON
Check CA-103 Display cable for
visible defects
Check that CA-103 at J12
connector is properly connected.
Check for corrosion at Display
PCB from leaking water
Measure voltage on J12:
Between pin 1 and 5 = 5 V
Between pin 9 and 10 = 3.3 V
Replace the Display PCB
If LED D110 is OFF.
Replace Bridge PCB.
No “Welcome” message on the
display and no sound during
start up.
Check LED D1, D2, D4 and D6
on the Power supply PCB
(replace fuses if necessary)
Verify all connections in CA-004
– Bridge power cable
For more information, click on
the following link “Bridge PCB”
on page 19, “Power Supply
PCB” page 14 and “Mains PCB”
page 13.

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 11
ERROR MESSAGES
Failure description
Reason
Solution
“NETWORK FAIL !!”
“CALL SERVICE”
Displayed after the unit is
switched ON.
Occurs when RS485
communication between the
“Foot control” and the “Bridge
PCB” fails.
RS-485 communication:
Brown cable
White cable
The footswitch is equipped with
the RS485 driver and the
Powerdriver PCB AO-137 is
equipped with the RS485
receiver:
The RS-485 communication bus
is established between the cable
Brown and white.
Connector J1 on the Foot control
and J14 Bridge com
Check the CA-003
communication cable is properly
connected between J14 “Bridge
PCB” and J32 Bridge Comm on
“Backplane PCB” in the unit.
A ground loop. A ground loop
can interfere with data by
distorting the RS485 signal
resulting in a network fail. If one
of the cable insulations is
damaged and one of the
conductors accidentally touches
a grounded metal object it can
cause a ground loop.
Check that the brown and white
communication cable on CA-009
“Foot control” and/or on CA-003
“Bridge Comm” cable are not
damaged.
Change the cables if damaged
If the cable is not damaged and
the message persists, either the
“PCB Foot control AN-373” or
the “Powerdriver PCB AO-137”
is defective.
Re-calibrate the Foot control.
Watch the How-to video on XO
CARE website
Consult a XO technician.
“FOOT CONTROL FAIL”
“CALL SERVICE”
Displayed after the unit is
switched ON.
Occurs when RS485
communication between the
“Foot control” and the “Bridge
PCB” fails.
Check that the CA-009 Foot
control cable connector is
properly connected to J14 “XO
Foot control” on the “Backplane
PCB” and that the cable is
connected properly to the foot
control.
Check that the cable is not
damaged.
Consult page 15 “Backplane
PCB” for more details

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 12
Visually: Check the LED D4 on
the foot control PCB.
The LED should blink fast.
Consult XO technician.
“POWER DRIVER FAIL!!”
“CALL SERVICE”
Displayed after the unit is
switched ON.
Occurs when CA-017 RS485
communication between the
“Power driver” and the “Bridge
PCB” fails.
Check the connectors of the CA-
017 RS-485 communication
cable connected to J6 on the
“Power driver” PCB and J3 on
the “Bridge PCB”.
Check the LED D6 on the power
driver PCB. Replace power driver
if necessary.
See page 22 for further details.
Consult XO technician.
“STAND CONTROL FAIL !!”
“CALL SERVICE”
Displayed after the unit is
switched ON.
Occurs when RS485
communication between the
“Stand Controller PCB” and the
“Bridge PCB” fails.
Check if the "Stand Controller
PCB” is properly connected to
J16 on the "Backplane PCB".
Verify the fuse F1 on “Stand
Controller PCB” by checking the
yellow LED D29 is ON.
For more info go to page 16.
Replace “Stand Controller PCB”
if necessary
Consult XO technician.
“WATER LEAK”
“CALL SERVICE”
Overflow in the water reservoir
(bottom of the unit)
Determine the cause of the leak
and overflow. In general, the leak
is due to overflow from the
mixing cups indicating that the
V27 and V39 valves do not close
properly.
Disassemble and clean the
valves V27 and V39, replace the
plunger gasket MR-150. Remove
the water from the overflow
reservoir and dry the S33 water
leak sensor.
“UNIT NOT READY”
One of the instruments is
activated upon unit start up.
On the bridge:
Check that all instruments are in
the rest position.
Remove the instrument bridge
cover:
Check the magnet on the
suspension roller AN-011 and the
hall sensor on the suspension
PCB is aligned.
Check the LED D110 on the
suspension PCB is OFF when
the instrument is in the rest
position.
LED ON= Instrument active
LED OFF= Instrument inactive

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 13
“NO WATER FLOW”
Displayed when the “backflow
prevention” mixing cup takes
more than 90 seconds to fill.
Check waterflow through the
water softener filter and the
water regulator and adjust if
necessary, to 2.3 bar.
See page 58 for more details on
the Mixing Cup Sensor PCB
functionality
Check function of the valve V27.
If necessary, disassemble, clean,
and replace gasket MR-150.
Check the main water valve V10.
“CHAIR SYNC FAILED”
Displayed when the chair
synchronization fails
Recalibrate the chair according
to the instruction “YB-755 - chair
synchronization”
Chair motors are powered by
230V from the “Mains PCB”.
See page 14 for further details.
Check the hall sensors for the
chair lift motor and back rest
motor. See page 74 for more
details.
If calibration fails, replace “Stand
controller PCB”.
“CODE BLOCK REQUIRED”
“CALL SERVICE”
Displayed when unit with
firmware v2.00 or higher has no
code block installed. This
message can’t be removed and
unit not operable in this mode.
Consult a XO technician.
“CS ERROR”
Displayed if the unit's firmware is
not complete or fails during
update.
Run a new firmware update.
Read carefully “YB-945 Update
XO4 and Flex firmware” before
performing the update.
Replace the Bridge PCB if
firmware update does not solve
the issue.
“MISSING DMX PCB”
Displayed if there is an error in the
MX motor circuit on the unit.
Verify that the “DMX PCB”
located on top of the Power
Driver PCB is not missing or
defective.
Verify that the cable CA-073/CA-
112 is connected correctly.
Verify that the Green LED on the
“Power Supply AO-136”is on.
Units from 11/2018 has no green
LED on the Power Supply”.
Check the output voltage on the
Power Supply is 32V +/- 0.5V.
See page 36 “Micro motor MX2”
for more information.
“WRONG INSTRUMENT”
Displayed if the menu’s “SUSP X”
and “SPCB X” (technician menu)
are not configured correctly
according to the active
Verify that the instrument is
positioned on the correct
suspension.
Verify the configuration of “SUSP

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 14
instrument.
X” and “SPCB X” in the
technician menu.
See page 23 for further details.
“WRONG SUSP PCB”
Displayed if the active instrument
is not compatible with the
suspension PCB, or if the “SPCB”
menu is not configured correctly.
Configure "SPCB 1-6" in the
technician menu.
“CHECK WHITE BOTTLE”
Displayed when the Water
disinfection bottle (white handle)
in the service hatch is empty.
Check that the parameter
“WATER CL” is set correctly
according to the unit
configuration. Consult the
“Technician menu” on page 26.
Replace the white bottle “XO
Water Disinfection” AO-980.
If the bottle is full...
Verify if the bottle is positioned
correctly.
Verify LED on the bottle
detection PCB is OFF.
LED OFF= Bottle full
LED ON= Bottle empty/missing
Verify connections on the cable
CA-033.
Check that the rubber part on the
sensor is not damaged or
squeezed. Replace if necessary,
part no. MG-880
More information can be found
“Water Disinfection System” on
page 49 and 50.
“CHECK YELLOW BOTTLE”
Displayed when the Suction
disinfection bottle (yellow handle)
in the service hatch is empty.
Check that the parameter
“SUCTION CL” is set correctly
according to the unit
configuration. Consult the
“Technician menu” on page 26.
Replace the yellow bottle
“XO Suction Disinfection”.
AN-354.
If the bottle is full.
Follow the instructions explained
in the chapter “CHECK WHITE
BOTTLE” above.
“SUCTION CLEAN FAIL”
“CALL SERVICE”
Displayed when the Suction
disinfection procedure fails. The
error can be caused when the
filling of the mixing cup takes
more than 90 seconds or takes
more than 4 minutes to empty
Check the function of the
“Sensor PCB” located in the
mixing cup. See page 58
Check the water supply to the
mixing cup.
Check that suction is available
Check that the yellow tubes are
reaching the bottom of the
mixing cup.
Check that the yellow tubes on
the service hatch is not clogged.
Consult a XO technician.

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 15
“MAINS PCB”
The "MAINS" PCB board purpose:
1. 230V general power supply connector.
2. Transformer power supply connectors.
3. Power supply for the lifting motor and the backrest motor of the chair
4. Halogen OP light connector power supply. (Only on AN-378)
5. Calling an assistant connector (relay)
6. Starting the suction motor (relay)
Units produced before September 2017 are equipped with an “AN-378” PCB board
Units produced after September 2017 equipped with the separate EMI filter are equipped with an
“AP-005”PCB board.
See Service Note dated 02 September 2017 on the XO Site page “Technical Service”.
Failure description
Reason
Solution
LED D3 is off (Power supply
chair)
Verify fuse F1 and/or F2
(fuse F1 removed from 10/2017)
Change fuse F1 and/or F2
LED D2 is off
Verify fuse F3 and/or F4
(F3, F4 & D2 removed from
Mains PCB 10/2017)
Change fuse F3 and/or F4
LED D1 is off
(transformer and power
supply)
Verify fuse F5 and/or F6
(fuse F6 removed from 10/2017)
Change fuse F5 and/or F6
LED D1 and D3 are OFF
Mains switch turned off
Fault in mains voltage supply
Fault in mains switch or mains
switch cable
Check that the voltage is reaching
the unit.
Check the clinic Mains switch.

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 16
“POWER SUPPLY PCB”
The “Power Supply PCB AN-371” transforms and manages the secondary voltages of the transformers
into precision voltages necessary for the operation of the unit. The secondary outputs are connected to
pin J1 and the precision voltage outputs are connected to pin J2.
Fuses F11 F12 F13 F14 protect the secondary outputs. LEDs D1, D2 D4 D6 indicate whether the
secondary output voltage is present. A set of fuses is available AN-305
Failure description
Reason
Solution
D1 LED is OFF (24VAC)
Fault on 24VAC power supply.
Verify / Change fuse F13.
D2 LED is OFF ±34VDC
Fault on 24VAC power supply.
Verify / Change fuse F12.
D3 LED is OFF ±34VDC
Fault on 24VAC power supply.
Verify / Change fuse F11.
D6 LED is OFF 5V, 12V,
24VDC
Fault on 18VAC power supply.
Verify / Change fuse F14.
All fuses OK, no light in LED
Replace transformer MH-650
If one of the fuses blows after
replacement
Track the overload or short
circuit
All LEDs on the “Power
supply PCB” are OFF and
LED’s on “Mains PCB” are
ON
Problem with the transformer
power supply.
Check that the transformer
connector is inserted properly
into J11 on the Mains PCB
board.
Check that transformer output
connector is inserted properly
into J1 on Power supply PCB
Replace Power supply PCB
Precision voltage measurement:
On “J2” on “Power Supply AN-371” See picture and explanation down below
Concerning the mentioned precision voltage on “J1 Stand” on “Bridge PCB AN-368”, consult page 23
for picture and explanations.
PIN
Volt
Explanations.
1 +34V
LED D2 & D4 indicates ±34V is available.
±34V is transformed by the “power driver
AO-137” placed in the bridge Used for the
rotation of the micromotor MC3 and for
the functionality of the curing lamp. Check
the ±34V on the “J1 stand” located on the
“Bridge PCB AN-368”
8 -34V
2
24VAC
LED D1 indicates that 24VAC is available.
LED D800 located on the “Bridge AN-368”
indicates the presence of 24VAC.
9
3
24VAC
10
4
5VDC
Consult the 5V Surge Protection session
on page 17
11
5
24VDC
LED D6 indicates that 24 VDC is available.
LED D191 located on the “Bridge PCB
AN-368” indicates the presence of 24VDC.
The fuse F1 on the “Bridge PCB AN-368”
protects the 24VDC on the “Bridge PCB
AN-368”.
12
6
GND 0V
13
14
7 12V
Available - Not used

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 17
5V OVERVOLTAGE PROTECTION
Protection against transient overvoltage’s that could damage or destroy electronic components and
PCB. It has a faster reaction than a fuse
NB: Only concerns the 5V of the unit generated on the “Power Supply PCB AN-371”.
The “Bridge PCB AN-368” is equipped with its own 5V DC/DC converter.
5V overvoltage protection affects : See the complete list in: “Backplane PCB” - 5V Connections
Control Pedal
“Foot Control Fail – Call service”
Displayed during start-up
phase
“Network Fail – Call service”
Joystick
Not possible to operate the chair
No message displayed
XO Operating light
Operating light does not switch on
No message displayed
“Water clean” and “suction
clean” sensors .
Sensors does not light No message displayed
Procedure:
•Check the LED D6 situated on the “Power Supply PCB AN-371” is lit. When the LED is OFF
indicates that either the fuse F14 is blown, or the transformer is defective
•
Remove the control pedal cover
•Measure the 5V on pin J1 of cable CA-009 - Pin 3 (Yellow +5V) and Pin 4 (Green GND)
If 5V is present, see other symptoms connected with the displayed message.
If the 5V is not present, switch off the unit:
•Disconnect all the cables mentioned in the list “BACKPLANE - 5V Connections” below, from the
“Backplane AN-369”.
•Disconnect also the cable connecting the “Power supply PCB AN-371” J2 to the “Backplane
PCB AN-369” J30
•Measure if the 5 Volt on J2 “Power Supply AN-371” is present between on the pins
1. +5V: Pin 4 et 11
2. GND: Pin 6, Pin 13, Pin 14.
If the 5 volts is not present change the “Power Supply AN-371”.
When the 5 Volt is present:
•Reconnect the cables one by one while checking that the 5V is still present.
•Beware: Switch off the Unit off between each single cable connection.
•It is suggested to reconnect the following cables first as they are the most exposed to the risk of
short circuit.
3. Control pedal.
4. Joystick
5. “Water clean” and “Suction Clean” system cable
See the list below for more information on measurement points and checks to be performed.

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 18
Cause:
Control Pedal
Check the “CA-009 Foot control” cable connected
from J14 “Backplane AN-369” to J1 in the control
pedal.
Pédale J1:
Pin 3: 5V (Yellow)
Pin 4: GND (Green)
Cause: Trapped when the seat moves when the
chair is raised or lowered.
XO Operating light
Check the “CA-012 Lamp Signal” cable connected
from J11 “Backplane AN-369”the connector
located in the Operating light arm.
CA-012:
Pin 2: 5V (Brown)
Pin 3: GND (Green)
Cause: Damaged cable connection, 5V is in
contact with the ground.
Preferably measure on the connector located in
the arm of the XO operating light
Joystick Base chair
Check the “CA-010 Joystick” cable connected from
J13 “Backplane AN-369” to J1 in the joystick
Joystick J1:
Pin 1: 5V
Pin 6: GND
Cause: Trapped when the seat moves when the
chair is raised or lowered.
“Water Clean” and “Suction Clean” system
In the service panel.
Check the “CA-008 S15” cable connected on J1 on
the AN-374 “Suction Clean dispenser level sensor”
PCB
Same for the “CA-033 S14” cable connected on J1
of the AN-374 “Water treatment dispenser level
sensor” PCB”
CA-008: Pin 1: 5V
Pin 4: GND
Cause: The cable may be damaged if the cable
clamps are too tight and the 5V is in contact with
the metallic part of the service panel.
Measure directly on the connector J1
“BACKPLANE”– 5V Connections
Cables
Measure
J4 Suct. Clean. System CA-008
5V:
Pin 6, 12, 16
GND:
Pin 2, 3, 5, 11
J5 Backflow Prev. CA-007
5V :
Pin 4
GND
Pin 3
J11 Lamp signal CA-012 5V : Pin 2
GND :
Pin 3
J12 Lift Sig. CA-047
5V :
Pin 2
GND :
Pin 3
J13 Joystick CA-010
5V :
Pin 1
GND :
Pin 6
J14 Foot control CA-009
5V :
Pin 3
GND : Pin 4
J29 Mains PCB Control CA-011
5V :
Pin 1
GND :
Pin 13
J30 Power Supply CA-005
5V :
Pin 4, 11
GND :
Pin 6, 13, 14
J33
Water detection
CA-029
5V :
Pin 2
J37 Water Treatment CA-033
5V :
Pin 3, 6
GND :
Pin 4

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 19
“BACKPLANE PCB”
The backplane is used as a support backbone structure for connecting PCB such as the
“
Stand
controller PCB”, “Peristaltic Pump controller PCB”, “Screen Power supply PCB” and cable connection
configuration.
Connections
Cables
Connections
Cables / PCB
J1 Chair signal
CA-001
J15 Assist signal
J3 Basic config.
CA-006
J16 CTL
“Stand Controller PCB”
J4 Suct. Clean. System
CA-008
AUX 1-6
“PC communication PCB”
J5 Backflow prev.
CA-007
“Screen Power supply PCB”
J8 Amalgam Separator
CA-035
“Peristaltic pump PCB”
J11 Lamp signal
CA-012
J30 Power Supply.
CA-005 Backplane Power cable.
J12 Lift signal
CA-047
J31 Bridge Power.
CA-004 Power cable
J13 Joystick
CA-010
J32 Bridge Comm.
CA-003 Signal cable
J14 Foot control.
CA-009
J24 to J26
CA-049 24V AC/DC cable XO4 & Flex

XO 4 & XO FLEX TROUBLE SHOOTING GUIDE
Version 3.30 20
“STAND CONTROLLER PCB”
The "Stand Controller PCB" controls all valves, level sensors, pumps, suction and patient chair signals
of the XO unit. Converts and manages all incoming / outgoing signals transmitted from or to the Bridge
PCB.
"Stand Controller PCB":
- Can only be positioned in the leftmost position on the Backplane PCB
- Equipped with a fuse F1 (ML-600).
- Yellow LED D29 indicates that 24VDC is available in the unit stand
- Provides power to the LED XO OP Light
- Stand controller PCB firmware can be updated via RS-485 bus
Failure description
Reason
Solution
D29 LED is OFF (24VDC)
Fuse F1 on Stand Controller is
blown
Replace fuse F1, 2A Nano type
fuse ref. ML-600.
SENSORS
VALVES AND PUMPS
S5
LEVEL DETECTOR FOR BACKFLOW PREVENTION
V4
CUP FILLER
S5B
LEVEL DETECTOR FOR WATER CLEAN
V7
CUSPIDOR FLUSH
S11B
MIXING CUP LOW LEVEL DETECTOR FOR SUCTION CLEAN
V39
WATER FLUSH / SUCTION CLEAN
S11T
MIXING CUP HIGH LEVEL DETECTOR FOR SUCTION CLEAN
V10
MAIN WATER VALVE
S14
LEVEL DETECTOR FOR WATER CLEAN
V12
MAIN AIR VALVE
S15
LEVEL DETECTOR FOR SUCTION DISINFECTION
V16
SMALL SUCTION Ø11
S33
WATER LEAK SENSOR
V17
LARGE SUCTION Ø16
S37C
CUP FILLER SWITCH
V22
SUCTION CLEAN VALVE
S37F
CUSPIDOR SWITCH
V27
WATER CLEAN
S38
SUCTION CLEAN SWITCH
V30
PRESSURISATION CONTAINER VALVE
S41
CUSPIDOR FLUSH SWITCH
V31
WATER CLEAN PUMP
V35
SUCTION CLEAN PUMP
Before replacing the “Stand Control AO-891”, always check the fuse F1 state.
Check and probe the cables controlling the 24V to detect any short circuits.
Below is a list of the faults connected to the “Stand Control PCB AO-891”.