Fresenius Medical Care T688 Series User manual

T688 Series
Service Manual
Medical Treatment Chair

Table of Contents
Fresenius Medical Care T688 Series 1
V1 Aug 2020
Contents
Serial Number ........................................................................................................................................2
Preventative Maintenance ......................................................................................................................3
Installation...............................................................................................................................................4
Troubleshooting ......................................................................................................................................5
Hand Control Programming ...........................................................................................................5
Power Source and Hand Control Indication.....................................................................................6
Recalibration....................................................................................................................................6
Service ....................................................................................................................................................8
Mechanical Parts Replacement.......................................................................................................8
Arm Rest Cushion removal / replacement..............................................................................8
Backrest Cushion removal / replacement..............................................................................8
Seat Cushion removal / replacement.....................................................................................9
All-Over Leg Rest Cushion removal / replacement ...............................................................9
Electrical Parts Replacement .......................................................................................................10
Control Box removal / replacement .....................................................................................10
Lift Column removal / replacement (T688) ..........................................................................12
Power Supply Cable removal / replacement .......................................................................13
Battery Backup removal / replacement................................................................................14
MJB Junction Box removal / replacement ...........................................................................15
Hand Control removal / replacement..................................................................................16
Backrest Actuator removal / replacement............................................................................17
Leg Rest Actuator removal / replacement ...........................................................................18
Castors..................................................................................................................................................19
Central Locking Castors removal / replacement ..........................................................................19
Contact..................................................................................................................................................21

Serial Number
Fresenius Medical Care T688 Series 2
V1 Aug 2020
Model number + MM/YY
(Date of Manufacture) +
four digits sequential
numbers
The Serial number and date of manufacture are located on a white label on the base of chair.
Note. The date of manufacture is in the following format: YYYY-MM-DD.
Note. The “ 0 ” in the serial number is a “zero”.
Note. The letters “ O ” and “ ” will not be used in the serial numbers.
Note. The label identifying the serial number is located on the base of the chair (see picture below).
Figure 1. Type Label
Figure 2. Type Label (Prior to June 2020)
Date of
Manufacture
Serial number
Model Number
of the treatment
chair: T688

Preventive Maintenance
Fresenius Medical Care T688 Series 3
V1 Aug 2020
Remove product from service before performing the preventive maintenance inspection. Check all
items listed during annual preventive maintenance, when required.
Inspection
Annually
Pass/Fail
Initial
Visual Inspection
☐
Check for any spills and overall condition of chair
☐
The upholstery and frame must be checked for damage (not
worn or torn)
☐
Power cord not frayed
☐
Check cables for cuts and wear
☐
Check for rust or corrosion of parts
☐
Check recline actions, steel constructions and fixings
☐
Check for broken welds
☐
All bolts must be checked
☐
Check actuators for damage including mountings
☐
Check all actuators are fitted properly
☐
Check all plastic covers (control box cover, hand controls)
☐
Check all visible electrical connections are tight
☐
Operational Inspection
☐
Check for recline, lift, and smooth leg rest operation (weight
loaded)
☐
Drive all actuators to the limit to ensure all motors operate
smoothly through cycle
Tray arm operation and tray covers (if fitted)
☐
Check swivelling arms for free and easy movement (if
applicable)
☐
Check all function of all buttons on Hand Controls (Nurse and
Patient)
☐
Check all memory functions and settings on nurse hand control
operate (Position 1, 2 and 3)
☐
Check castors for locking, easy movement and corrosion
☐
Central brake operates or individual castors brake
☐
Check if battery is charging when the power supply cable is
connected to the wall outlet
☐
Check if the chair label exists on the base of the chair
☐
Electrical Safety Test
☐
Product serial number:
Completed by:
Date:
Comments:

Installation
Fresenius Medical Care T688 Series 4
V1 Aug 2020
At all times, when positioning the chair, care should be taken to ensure that no part of the chair
comes into contact with any equipment or structures, particularly during emergency
procedures.
It is important to ensure that any staff members who are operating the chair have been trained by
the manufacturer or its agent prior to use.
The installation procedure is as follows:
1. Position the chair. Do not position the chair so that it is difficult to disconnect the chair from
the mains power.
2. Remove any temporary ties or packaging.
3. Connect the power cord to an approved power supply for the relevant country as indicated by
the label.
WARNING: To avoid risk of an electric shock, this chair must only be connected to supply
mains with protective earth.
4. Test the chair by taking it through its complete range of movements.
The power cord should be connected to the power point and the power point should be switched
on. The backup battery (if fitted) will recharge automatically and slow to trickle charge when full.
It is important to charge the backup battery for a minimum of 24 hours before use of the chair.

Troubleshooting
Fresenius Medical Care T688 Series 5
V1 Aug 2020
In the event the chair fails to operate correctly, please take the following steps prior to contacting
Fresenius Medical Care or its authorised agent.
1. Check that the mains power outlet is active.
2. Check that the power cord is not damaged or worn. Check that the chair is connected into the
mains power outlet and switched on correctly, as indicated by the green indicator light on the
nurse’s hand control.
3. Ensure that the battery has been on charge for 24 hours minimum. This should occur at least
every 5 days.
4. Ensure there are no damage or cuts in the cables to the hand controls or actuators.
5. Determine which functions are not operating as follows:
Problem / Failure
Action / Solution
The leg rest motor (vertically mounted under the
seat)
Depress the hand control button for the leg rest
and the leg rest should raise or lower.
The backrest motor (mounted behind the
backrest)
Depress the hand control button for the backrest
and the back should raise or lower.
The lift column (mounted on top of the base)
Depress the hand control button for the chair
height control and the chair should raise or
lower.
Take note of the serial number of the chair. This information can be found on the Type Label
(Figure 1 or 2. Type Label –Serial number location section) attached to the chair.
If unsure about any aspect of the above steps, please contact Fresenius Medical Care Seating at the
contact details provided at the end of this service manual (see Contact Information section).
➢Hand Control –Programming
Note.This can only be done using the nurse’s hand control. A maximum of three positions may be
programmed into the memory.
1. Position the chair to the desired position using the up & down arrows for the backrest, whole
chair and leg rest.
2. When the chair is in the desired position, hold down the S (store) button for five seconds until
the beep sounds.
3. Once the beep is sounding, select one of the numbers, 1, 2, or 3 and press it within two
seconds to store the pre-programmed position. When completed the system will beep two
times to confirm.

Troubleshooting
Fresenius Medical Care T688 Series 6
V1 Aug 2020
➢Power Source and Hand Control Indication
LED “Amber” Off and LED “Green” On indicates Mains is on and Battery is
fully charged.
LED “Amber” On and LED “Green” Off indicates Battery is in normal use.
LED “Amber” blinking and LED “Green” Off indicates Battery is in normal
use and requires charging.
LED “Amber” ON and LED “Green” ON indicates mains is on and battery is
charging.
LED “Amber” Off and LED “Green” Off indicates Mains is not on and battery
requires charging. Chair will not operate.
LED “Amber” blinking and LED “Green” blinking and indicates a system
error.
Note. When the chair is not connected to the mains, press any button on the nurse hand control to
restart the application and check the indication lights. Application will return to sleep mode within 2
minutes with no button pressed.
➢Recalibration
•For T688 Treatment Chair
If there is a loss of feedback from any of the actuators, a ‘position lost’ beep will be heard from the
control box when any button is pressed.
Recalibrate T688 Series Chair using the nurse’s hand control as follows:
➢Stage 1 –Clear System Faults
Press both of the Up and Down arrow buttons of the chair height function simultaneously.
If successful a constant beeping will be heard. Hold until the beeping stops
(approximately five seconds).
Note. Both buttons must be activated at exactly the same time. If beeping does not start,
repeat until successful.
➢Stage 2 –Initialise the System (Process 1)
Press both of the Up and Down arrow buttons for the Backrest function simultaneously and
hold until all the actuators have stopped moving. This will drive the Backrest actuator into the
fully retracted (down), the Leg rest actuator into the fully retracted (down) position and the
Height actuator into the fully retracted (down) position. When completed the system will beep
two times to confirm.
Note. If the system does not beep twice when all of the actuators have stopped, please contact
Fresenius Medical Care or your local representative for further assistance.
If the chair does not respond to Process 1, please follow the instructions below (Process 2).

Troubleshooting
Fresenius Medical Care T688 Series 7
V1 Aug 2020
➢Stage 2 –Initialise the System (Process 2)
Press and hold the “Backrest Down”button. Hold the button for one second after the actuator
has stopped moving.
Press the “Height Down”button. Hold the button for one second after the actuator has
stopped moving.
Press the “Leg rest Down” button. Hold the button for one second after the actuator has
stopped moving.
Note. The chair’s positions can be reprogrammed via the nurse hand control. Refer to
instructions in section: Hand Control –Programming.
•For T688B Treatment Chair
If there is a loss of feedback from any of the actuators, a ‘position lost’ beep will be heard from the
control box when any button is pressed.
Recalibrate T688B Series Chair using the nurse’s hand control as follows:
➢Stage 1 –Clear System Faults
Press both of the Up and Down arrow buttons of the chair height function simultaneously.
If successful a constant beeping will be heard. Hold until the beeping stops
(approximately five seconds).
Note. Both buttons must be activated at exactly the same time. If beeping does not start,
repeat until successful.
➢Stage 2 –Initialise the System
Press both of the Up and Down arrow buttons for the Backrest function simultaneously and
hold until all the actuators have stopped moving. This will drive the Backrest actuator into the
fully retracted (down), the Leg rest actuator into the fully retracted (down) position and the
Height actuators into the fully retracted (down) position. When completed the system will beep
two times to confirm.
Note. If the system does not beep twice when all of the actuators have stopped, please contact
Fresenius Medical Care or your local representative for further assistance.

Service
Fresenius Medical Care T688 Series 8
V1 Aug 2020
➢Mechanical Parts Replacement
Arm Rest removal / replacement
•To remove the arm rest:
1. Apply the chair brakes.
2. To avoid unnecessary bending, press the memory button 3 on the hand control to raise the chair
to a suitable working height.
3. Unlock the arm rest by grasping the black handle on the side of the chair (Locked Position).
4. Pull the handle away from the chair until the handle is at a right angle to the chair (Unlocked
Position).
5. Pull the arm rest post straight up and out of the arm rest holding bracket.
Note. Depending on the arm rest type, it can weigh up to 6.5kg.
•To replace the arm rest:
*Repeat the steps in reverse.
1. Position the black handle on the side of the chair at a right-angle to the chair (Unlocked Position).
2. Slide the arm rest post into the holding bracket until the desired height is achieved.
3. Relock the arm rest by pushing the black handle back to its original position (Locked Position).
Backrest cushion removal / replacement
•To remove the backrest:
1. Apply the chair brakes.
2. To avoid unnecessary bending, press the memory button 3 on the hand control to raise the chair
to a suitable working height.
3. Apply gentle force at the top rear of the backrest to unclip the plastic holders from the chair frame
and lift the backrest up away from the chair.
•To replace the backrest:
*Repeat the steps in reverse.
1. Apply the chair brakes.
2. Ensure the metal strip at the base of the back rest sits on the back frame of the chair.
3. Once in the correct position, push the top of the back rest into place ensuring the plastic clips
properly lock onto the chair frame.

Service
Fresenius Medical Care T688 Series 9
V1 Aug 2020
Seat cushion removal / replacement
•To remove the seat cushion:
1. Apply the chair brakes.
2. To avoid unnecessary bending, press the memory button 3 on the hand control to raise the chair
to a suitable working height.
3. Place hands at the front of the seat (near where the knees would be positioned) and apply a
gentle pulling force upwards. The plastic clips located on the seat will come away from the frame.
4. Lift the seat cushion up and away from the frame.
•To replace the seat cushion:
*Repeat the steps in reverse.
1. Position the metal strip on the back of the seat so that it fits into the receiving ledge located on
the chair frame.
2. Ensure the leg rest flap is attached to the round frame tube.
3. Position the plastic clips located at the front of the seat onto the round frame tube.
4. Ensure the frame and clips are properly aligned before applying a gentle downwards force.
All-Over Leg Rest removal / replacement
•To remove the All-Over Leg Rest:
1. Apply the chair brakes.
2. To avoid unnecessary bending, press the memory button 3 on the hand control to raise the chair
to a suitable working height.
3. Locate the elastic loops under the leg rest and unclip from the pastic anchors.
4. Repeat this step in the gap between the seat and the back rest. It may be easier if the backrest is
removed.
•To replace the All-Over Leg Rest
*Repeat the steps in reverse.
1. Attach the elastic loops to the anchor points located between the seat and the back rest.
2. Attach the elastic loops to the anchor points located under the leg rest.

Service
Fresenius Medical Care T688 Series 10
V1 Aug 2020
C
➢Electrical Parts Replacement
Control Box removal / replacement
Figure 3. Top frame Figure 4. Cables on Control box
Figure 5. Control Box
•To remove the Control Box:
1. Apply the chair brakes.
2. Raise the chair to its highest position, if applicable.
3. Disconnect the mains power supply cable from the wall outlet.
4. Remove the seat cushion from the chair, to access the top frame (Refer to Seat Cushion removal /
replacement section on page 9).
5. Undo the bolt (A) that holds the earth point cable (Figure 3).
6. Press in the red retainer clip, to allow the power supply cable to be removed.
7. Disconnect the two cables from the top of the control box (Figure 3) (power supply cable (B) and
battery (C)).
8. Once disconnected, undo the two bolts (D) head screws (Figure 3).
A
B
C
D
E
Control Box
F
SLIDE

Service
Fresenius Medical Care T688 Series 11
V1 Aug 2020
9. Disconnect all the cables (E) from the control box (Figure 4).
Note: It is recommended to number the cables while disconnecting them,to ensure they are
connected into the corresponding ports of the new control box.
10.Once the control box disconnected, undo the bolt and nut (F) located on the side of the bracket
and slide control box as directed in Figure 5.
•To replace the Control Box:
1. Reinstall the mounting bracket onto the new control box.
Note: When reinstalling the mounting bracket, do not overtighten the bolt and nut. Tighten the bolt
until it makes initial contact with the plastic housing of the control box.
2. Reconnect all the cables and mount the control box back onto the top frame.
3. Refit the seat cushion.
Note. Recalibration and reprograming are required after replacing the control box.

Service
Fresenius Medical Care T688 Series 12
V1 Aug 2020
Lift Column removal / replacement (T688)
Figure 6. Top Frame Figure 7. Lift Column Base
•To remove the Lift Column:
1. Apply the chair brakes.
2. Disconnect the mains power supply cable from the wall outlet.
3. Remove the seat cushion and the back rest (Refer to Backrest and Seat Cushion removal /
replacement section on page 8-9).
4. Remove the four mounting bolts (G) from the top of the column (Figure 6). Undo the four bolts
using a T40 torx driver.
5. Lift the whole chair assembly off the column (Two people required).
6. Position the chair on its back (see Figure 7).
7. Remove the four mounting bolts (H) located at the bottom of the column (Figure 7).
•To replace the lift column:
1. Place the new column to the base and the four mounting bolts.
2. Place the chair upright on its castors.
3. Reposition the chair assembly onto the column.
4. Reposition the four mounting bolts of the column onto the top frame.
5. Refit the seat and backrest cushions.
G
G
H
H

Service
Fresenius Medical Care T688 Series 13
V1 Aug 2020
Power Supply Cable removal / replacement
Figure 8. Top Frame
•To remove the power supply cable:
1. Apply the chair brakes.
2. Raise the chair to its highest position, if applicable.
3. Disconnect the mains power supply cable from the wall outlet.
4. Remove the seat cushion (Refer to Seat Cushion removal / replacement section on page 9).
5. Undo the bolt (J) that holds the earth point wire in place (Figure 8).
6. Simultaneoulsly, press-in the red retainer clips on each side of the power cable (I), to enable
the removal of the cable (Figure 8).
•To replace the power supply cable:
1. Connect the new power cable through the top frame, onto the control box.
2. Reattach the earth point wire.
3. Refit the seat cushion.
J
I

Service
Fresenius Medical Care T688 Series 14
V1 Aug 2020
Battery
Backup
Battery Backup removal / replacement
Figure 9. Top Frame Figure 10. Battery Backup
•To remove the Battery:
1. Apply the chair brakes.
2. Raise the chair to its highest position, if applicable.
3. Disconnect the mains power supply cable from the wall outlet.
4. Remove the seat cushion (Refer to Backrest and Seat Cushion removal / replacement
section on page 8-9).
5. Undo the four screws (K) located on the left side of the top frame, to allow the removal of the
battery (Figure 9).
6. Disconnect the battery cable from the control box (Figure 4, (E), Page 10).
•To replace the Battery:
1. Connect the cable of the new battery to the control box.
2. Reposition the battery underneath the top frame, to its initial position.
3. Insert the four screws into the top frame.
4. Refit the seat cushion and backrest.
K
K

Service
Fresenius Medical Care T688 Series 15
V1 Aug 2020
MJB
Junction
Box
MJB Junction Box removal / replacement
Figure 11. Top Frame Figure 12. MJB Junction Box
•To remove the MJB Junction Box:
1. Apply the chair brakes.
2. Raise the chair to its highest position, if applicable.
3. Disconnect the mains power supply cable from the wall outlet.
4. Remove the seat cushion (Refer to Seat Cushion removal / replacement section on page 9).
5. Undo the retention clip (N) from the MJB junction box using a screwdriver, located underneath
the chair (Figure 12).
6. Disconnect all the cables/ports (L) connected into the MJB junction box (Figure 12).
7. Undo the two bolts (M) located on the right side of the top frame, to allow the removal of the
MJB junction box (Figure 11).
•To replace the MJB Junction Box:
1. Reposition the new MJB junction box underneath the top frame.
2. Insert the two bolts that holds the MJB junction box into the top frame.
3. Reconnect all cables/ports that were previously connected into the MJB junction box.
4. Refit the seat cushion.
L
M
N

Service
Fresenius Medical Care T688 Series 16
V1 Aug 2020
Hand Control (Nurse or Patient hand control) removal / replacement
Figure 13. Hand Controls
•To remove the Hand Control:
1. Apply the chair brakes.
2. Raise the chair to its highest position, if applicable.
3. Disconnect the mains power supply cable from the wall outlet.
4. Undo the retention clip (N) from the MJB junction box using a screwdriver, located
underneath the chair (Figure 12, page 15).
5. Disconnect the cable of the Hand Control (L), from the MJB junction box (Figure 12, page
15).
•To replace the Hand Control:
1. Connect the new hand control to the MJB junction box.
2. Place the retention clip back on the MJB junction box.
3. Reconnect the power supply cable to the wall outlet.

Service
Fresenius Medical Care T688 Series 17
V1 Aug 2020
Actuator Cable
(O)
Backrest actuator removal / replacement
Figure 14. Backrest Actuator
•To remove the Backrest actuator:
1. Apply the chair brakes.
2. Disconnect the mains power supply cable from the wall outlet.
3. Disconnect the actuator cable (O) (see Figure 14 and Actuator cable).
4. Undo and remove the two bolts (P) and (Q) located at each end of the actuator.
5. Remove the Backrest actuator.
•To replace the Backrest Actuator:
1. Insert the Backrest actuator.
2. Replace the two bolts connecting the actuator to the frame.
3. Connect the actuator cable.
Note. Recalibration is required after replacing the Backrest actuator.
Note. Check of programming is recommended only.
P
O
P
Q

Service
Fresenius Medical Care T688 Series 18
V1 Aug 2020
Leg Rest actuator removal / replacement
Figure 15. Leg Rest actuator Figure 16. Leg Rest actuator
•To remove the Leg Rest actuator:
1. Apply the chair brakes.
2. Raise the chair to its highest position, if applicable.
3. Disconnect the mains power supply cable from the wall outlet.
4. Disconnect the actuator cable (R) (Figure 15).
5. Undo and remove the two bolts (S) and (T) located at each end of the actuator (Figure 15-
16).
6. Remove the Leg Rest actuator.
•To replace the Leg Rest actuator:
1. Insert the Leg Rest actuator.
2. Replace the two bolts connecting the actuator to the frame.
3. Connect the actuator cable.
Note. Recalibration is required after replacing the Leg Rest actuator.
Note. Check of prgramming is recommended only.
R
S
T

Service
Fresenius Medical Care T688 Series 19
V1 Aug 2020
Blue brake pedal
Metal Plate
Nylon Pedal
Stopper
Central Locking Castors removal / replacement
Figure 17. Central Locking Castor Figure 18. Castor
Figure 19. Castor
Note. Please contact FMC Seating (Australia) for Central Locking Castor Replacement on
chairs with the following serial number: 688T08146702 or with a manufacturing date prior to
August 2014.
•To remove the Central Locking Castor:
1. Apply the chair brakes.
2. Raise the chair on a block of approximately 15 cm height.
Note. Locking the opposite individual castors will help in stabilizing the chair prior to tilting.
3. Remove the screw and nut (V) attached to each blue braking pedal, to remove the central
locking bars (Figure 17).
4. Remove the black rubber plug and undo the bolt (U) (Figure 18).
Note. Heat gun may be required to undo the bolt.
5. Remove the nylon pedal stopper and the metal plate located over the castor (Figure 18).
V
U