KERN TACJ User manual

KERN & Sohn GmbH
Ziegelei 1
D-72336 Balingen
E-Mail: [e-mail]
Tel: +49-[0]7433- 9933-0
Fax: +49-[0]7433-9933-149
Internet: www.kern-sohn.com
Service manual
Analytical balance
KERN TACJ/TACS
Version 1.2
2019-12
GB
TACJ/TACS-SH-e-1912

2 TACJ/TACS-SH-e-1912
GB
KERN TACJ/TACS
Version 1.2 2019-12
Service manual
Analytical balance
Basic information
Grundlegende Hinweise
The device must be repaired only by trained specialist staff or personnel with pro-
fessional formation (such as a repair-specialist accredited by law
concerning verification).
The service manual is obligatory for repair work.
After repair, original conditions of the device have to be restored.
Only original spare parts should be used.
Instructions about conformity-evaluated scales:
Repair must be carried only at 100% compliance with the type approval. A viola-
tion of this specification will result in a loss of the type approval!
After successful repair the balance will have to be reverified before it can be used
again in a statutorily regulated field.
Das Gerät darf nur von geschultem oder beruflich ausgebildetem Fachpersonal (z. B.
eichrechtlich anerkannter Instandsetzer) repariert werden.
Die Serviceanleitung ist bindend für Reparaturen.
Das Gerät muss nach erfolgter Reparatur wieder in den Originalzustand zurückversetzt
werden.
Es dürfen nur Originalersatzteile verwendet werden.
Hinweis zu konformitätsbewerteten Waagen:
Reparatur darf nur in 100% -iger Übereinstimmung mit der Bauartzulassung erfolgen.
Ein Verstoß gegen diese Vorgabe führt zum Erlöschen der Bauartzulassung!
Nach erfolgreicher Reparatur muss eine Nacheichung erfolgen, um die Waage wieder
im gesetzlich geregelten Bereich verwenden zu können.

TACJ/TACS-SH-e-1912 3
Table of Contents
1Operations for Adjus tment ................................................................................5
1.1 Entering the Service Mode ............................................................................................................5
1.2 Contents of Service Menu .............................................................................................................6
1.3 Service Mode Functions................................................................................................................7
2Disass embling and As s embling the B alance.................................................10
2.1 Precautions.................................................................................................................................. 10
2.2 Inspecting the Balance Interior (Removing the Case and Pan Supporter) ........................... 12
2.3 Replacing Components .............................................................................................................. 15
2.3.1 Replacing the Front Glass ASSY (C8).......................................................................................... 15
2.3.2 Replacing the Side Glass ASSY (C6, C7)..................................................................................... 16
2.3.3 Replacing the Roof Glass ASSY (C5)........................................................................................... 16
2.3.4 Replacing the Display Board ASSY (B2)....................................................................................... 16
2.3.5 Replacing the Power Board ASSY (B4)........................................................................................ 17
2.3.6 Replacing the Analog Board ASSY (B3)....................................................................................... 18
2.3.7 Replacing the Weight Loader ASSY (27)...................................................................................... 19
2.3.8 Replacing the Unit ASSY (1)......................................................................................................... 20
2.3.9 Replacing the Detector ASSY (U11) ............................................................................................. 21
2.3.10 Replacing the Force Coil ASSY (L1)......................................................................................... 22
2.3.11 Replacing the Stopper Plate (U14) ........................................................................................... 25
2.3.12 Replacing the Stopper Lever (U15) .......................................................................................... 25
3Checking the E lectronic B oard........................................................................27
3.1 Display Board ASSY (B2) ........................................................................................................... 27
3.2 Analog Board ASSY (B3)............................................................................................................ 28
3.3 Preamp Board ASSY (B1)........................................................................................................... 28
3.4 Power Board ASSY (B4).............................................................................................................. 29
4Hardware Adjustment.......................................................................................30
4.1 Adjusting the Detector ASSY (U11) Height............................................................................... 30
4.2 Adjusting the Tilt Error ............................................................................................................... 31
4.3 Adjusting the Balance................................................................................................................. 32
4.4 Adjusting the Cornerload Error ................................................................................................. 33
5S oftware Adjus tment........................................................................................35
5.1 EEPROM Initialization................................................................................................................. 35
5.2 Model Selection........................................................................................................................... 36
5.3 Releasing and Setting the Setting Information Lock............................................................... 36
5.3.1 Releasing the Setting Information Lock......................................................................................... 37
5.3.2 Setting the Setting Information Lock ............................................................................................. 37
5.4 Inputting Weight Values for Linearity Adjustment................................................................... 38
5.5 Linearity Adjustment................................................................................................................... 38
5.6 Internal Weight Calibration (PCAL) (ACJ Only)........................................................................ 39
5.6.1 Operation Procedure and Process................................................................................................ 39
5.7 Sensitivity Calibration................................................................................................................. 42
5.7.1 Menu settings „I.CAL“ / „E.CAL“.................................................................................................... 42
5.7.2 Adjustment with external weight (KERN ACS).............................................................................. 43
5.7.3 Adjustment with internal weight (KERN ACJ)................................................................................ 44
5.8 Weight Loader Mechanism Operation Check........................................................................... 45
5.8.1 Operation Procedure and Process................................................................................................ 46
5.8.2 Errors............................................................................................................................................. 46
6EEPROM............................................................................................................47
6.1 PRINT Operations........................................................................................................................ 47
6.2 Data Edit (EDIT) Operations ....................................................................................................... 48
6.3 Backup (BKUP) Operations........................................................................................................ 48

4 TACJ/TACS-SH-e-1912
6.4 Download (RESTR) Operations.................................................................................................. 49
6.5 All Initialization (INIT) Operations.............................................................................................. 49
7Performance Inspection .................................................................................. 50
7.1 Reproducibility............................................................................................................................. 50
7.2 Cornerload Error.......................................................................................................................... 50
7.3 Linearity........................................................................................................................................ 51
7.4 Tilt Error........................................................................................................................................ 51
8Problems and S olutions .................................................................................. 53
8.1 General Problem Solutions ........................................................................................................ 53
8.2 Error Display ................................................................................................................................ 55
8.2.1 User Mode Errors .......................................................................................................................... 55
8.2.2 Service Mode Errors...................................................................................................................... 56
9Troubleshooting............................................................................................... 57
9.1 Display Won't Appear.................................................................................................................. 57
9.2 Key Operation Does Not Work................................................................................................... 57
9.3 “ERR C” is Displayed.................................................................................................................. 58
9.4 “ERR H” Is Displayed.................................................................................................................. 60
9.5 When Power Is Switched On, Display Stops at “Software Version”...................................... 60
9.6 Trouble of Weight Loader........................................................................................................... 61

TACJ/TACS-SH-e-1912 5
1 Operations for Adjustment
For the general operations method, see the User's Manual for the ACJ/ACS Series.
1.1 Entering the Service Mode
Series ACS:
Move from user mode to service mode as follows.
1. In the user mode mass display state, keep pressing [ON/OFF] and [PRINT] keys
together for aprox. 3 seconds.
2. Release the keys
3. Press down on the [CAL] and [MENU] keys together for approx 3 seconds.
4. The password input display appears.
5. Use the arrow keys to input numbers.
6. Input 00321 as the display maintenance mode password, and press the [TARE]
key.
7. When the password is approved, the service mode opens.
Alternately, you can enter service mode by inputting the display maintenance mode
command "@SVC=321" from the PC.
Series ACJ:
1. Break the seal on base (left side). By pressing the sealing switch on the display
board (a push button on the left from your view of the board), connect the AC
adapter and when “CHE 2” is displayed, release the switch.
2. After a short time the display appears “OFF”. Press the [ON/OFF] key once. Now
you are in weighing mode.
3. Enter the Service Mode following the same procedure as with standard models
ACS (see above).

6 TACJ/TACS-SH-e-1912
1.2 Contents of Service Menu

TACJ/TACS-SH-e-1912 7
Items in the figure framed in thick lines denote execution items, while those framed in
thin lines denote menu items.
Shaded items are not displayed when the setting information lock is on. Use the arrow
keys to move between items.
Key
Explanation
→
(Print)
Move to an item in a subordinate menu. If the menu item to the left of
the arrow has no asterisk mark and is also shaded, pressing the [Enter]
key on that item opens a subordinate menu item. (In other words, if the
higher menu accepts the [Enter] key even if it has no enable/disable
switch, pressing the [Enter] key opens the subordinate menu.) To open
the menu from the mass display state, use the [MENU] key instead of
the [→] key.
ESC (ON/OFF)
Return to the item in the higher menu.
↓
(MENU)
Move to the items in order.
↑
(UNIT)
Move to the items in revers order.
1.3 Service Mode Functions
Function
Outline
Error display
Error display Displays error codes for errors
that have occurred in user mode.
If no errors have occurred when service mode
is opened, the error display does not appear.
Model name display
Displays the model name setting.
Destination display
Displays the destination setting.
Ex.:
JPN =
Japan
SI =
Countries and regions that recog-
nize SI units only
EXP =
Overseas (excluding Southeast
Asia)
ASIA =
Southeast Asia
TA =
Type Approval

8 TACJ/TACS-SH-e-1912
Function
Outline
Software Ver. display
Displays the currently mounted software ver-
sion.
Ex.: 1.00, ##, XX
In principle, 1.00 is the version number for
hardware changes.
Next, ## is the version number for manuals
and other documentation changes.
Finally, XX is the version number for bug fixes
and other minor changes.
Span temperature coefficient display
Displays the span temperature coefficient for
before and after aging.
Zero drift display
Displays the amount of zero drift before and af-
ter aging.
AD value display
Mass data (WAD) dis-
play
Displays mass data as received from AD con-
verter. (Data subjected to smoothing)
Temperature data
(TAD) display
Digitally displays voltage of temperature sensor
mounted
Temperature-corrected
mass
Displays WAD mass data subjected to temper-
ature correction. (Data subjected to smoothing)
Linear-corrected mass
data
Displays OAD mass data subjected to linearity
correction.
Absolute load(WG)
display
Displays mass values shown in g units that are
subjected to all correction processing. Displays
mass values not subjected to zero setting or
tare weight.
Sensitivity calibration
Executes sensitivity calibration using the same
operation
Weight loader
Return to initial position
Internal weight loader system returns to initial
position.
Load and unload
Internal weight is loaded or unloaded to unit
ASSY.
Linearity adjust-
ment
Linearity adjustment
Executes the adjustment operation for calcula-
tion of the linearity correction coefficient.
Weight value input for
linearity
Inputs the reference weight value used for line-
arity adjustment.

TACJ/TACS-SH-e-1912 9
Function
Outline
Model selection
Selection of the model name automatically sets
the basic information for weighing capacity,
minimum display, and reference mass for ad-
justment.
Shipping settings
Unit for Japan
Set the units users can use, depending on
shipping destination.
SI unit
Overseas unit
Unit for Asia
Type approval
Serial No. input
Top 5 digits
Input the top 5 digits of serial No.
Bottom 5 digits
Input the bottom 5 digits of serial No.
OEM
On
Sets to OEM model
Weighing capacity
Changes to weighing capacity
Minimum display
Changes to minimum capacity
Setting information lock (error check)
Prevents changes to the model, OEM, ship-
ping, and S/N settings. When the lock is active,
all error checks are enabled.
NVRAM
Data print
Outputs data saved in EEPROM to a dedicated
printer.
Data edit
Edits data saved in EEPROM on balance dis-
play unit.
Backup
Of the data saved in EEPROM, backs up tem-
perature correction coefficient, linearity correc-
tion coefficient, and model setting status data
to a Flash memory.
Download
Writes to EEPROM the data backed up on a
Flash memory.
All initialize
Initializes all data saved in EEPROM.
END
Ends service mode

10 TACJ/TACS-SH-e-1912
2 Disassembling and Assembling the Balance
2.1 Precautions
1. Pull the connector straight out when disconnecting. Never pull it out at a bent an-
gle.
*Pulling out at a bent angle could bend the terminal pins, making it difficult to re-
insert the connector.
Fig. 2-1
2. When assembling the base unit ASSY (2) and case ASSY (3), check that the
power board ASSY (B4) connector is firmly inserted.
*An insufficiently inserted connector could lead to instability in the display.
Connector
Fig. 2-2
3. When performing disassembly and assembly of the unit ASSY (1), insert the
lever fixing pin (J1) into the lever fixing hole on the top of the OPF.
*Lift up on the lever ASSY (1) to insert the pin. Proceed carefully to avoid
scratching the * elastic support.

TACJ/TACS-SH-e-1912 11
4. Use a controlled torque driver to tighten the screws to the torques shown in the
table below.
Screw
Torque [kgf•cm]
M2
1
M2.5
2.5
M3 pan head
9
M3 hexagonal socket head bolt
15
M4 pan head
18
M4 hexagonal socket head bolt
30
M5 hexagonal socket head bolt
35

12 TACJ/TACS-SH-e-1912
2.2 Inspecting the Balance Interior (Removing the Case and Pan Supporter)
[Disassembly]
1. Extract the AC adapter and remove the pan (6), pan supporter ASSY (4), and
wind shield ring (7).
2. Remove the screws on the back surface of the balance (truss M3 × 5 (4
screws)), and remove the rear cover (13).
3. Remove the screw covers (B24), and the screws (2 screws) on the back of the
balance, and remove bolt P4 M4 × 25 (2 bolts).
•To remove the screw covers (B24), insert something with a sharp tip
(tweezers, etc.) into the screw cover (B24) hole, and then lift up.
•When removing the screw covers (B24), be careful to avoid damag-
ing the case (C1) and the screw covers (B24).
Fig. 2-3 Fig. 2-4
4. Remove screw P3 M4 × 20 (2 screws) (B23) on the bottom and front of the bal-
ance.
Fig. 2-5

TACJ/TACS-SH-e-1912 13
5. With the case ASSY (3) lifted up, extract the connector inserted into the switch
board ASSY (C4), and remove the case ASSY (3).
* Be careful to avoid deforming the case (C1) when positioning.
•Be careful to avoid deforming the rib on the inside.
•Be careful to avoid deforming the front display.
* The display board ASSY (B2) and power board ASSY (B4), etc., can be in-
spected while in this position.
Connector
Fig. 2-6
6. Remove screw P4 M4 × 8 (7 screws), and remove the unit cover (B5).
* The unit ASSY (1), analog board ASSY (B3), and the weight loader ASSY
(27), etc., can be inspected while in this position.
[Assembly]
1. With the unit cover (B5) as the base, use screw P4 M4 × 8 (7 screws) to tighten.
*With the unit cover (B5) rear screw as the base, align with the center of the
pan supporter axis and the 15.5-dia. hole to amount the other screws. (Fig.
2-7)
*Mount the unit cover (B5) so that the cable is flat. At this time, be careful
to avoid pinching the cable.
*Check that there is no gap between the base ASSY (B1) and the unit cover
(B5).
Fig. 2-7
Fig. 2-8

14 TACJ/TACS-SH-e-1912
2. With the case ASSY (3) lifted up, insert the connector into the switch board
ASSY (C4), and set the case ASSY (3) into the base unit ASSY (2).
* Be careful to avoid damaging the power board ASSY (B4) and cable when
covering the base unit ASSY (2) with the case ASSY (3).
* Be careful to ensure that the case ASSY (3) does not touch the pan sup-
porter axis when covering the base unit ASSY (2) with the case ASSY (3).
* Check the connector connection conditions on the power board ASSY
(B4).
3. Tighten the case ASSY (3) and base unit ASSY (2) in two locations in back (bolt
P4 M4 × 25) and two locations on the bottom front side (P3 M4 × 20).
4. Attach the screw covers (B24) in two locations on the back of the balance.
* When attaching the screw covers (B24), insert the protrusion on one side
of the screw cover (B24) into the case (C1) hole and then push down on the
top of the screw cover (B24) to attach.
* Attach so that the screw cover (B24) hole is on the back side.
Fig. 2-9 Fig. 2-10 Fig. 2-11
5. Mount the rear cover (13) (truss M3 × 5 (4 screws).
6. Align the anti-blow ring (11) and the center of the pan supporter axis, and mount
the anti-blow ring (11) and wind shield plate (12). (Fixing screw: Anti-blow ring
(11) → Screw P3 M2.5 × 6 (2 screws), Wind shield plate (12) → Screw P4 M3 ×
6 (2 screws)
Fig. 2-12
7. Set the pan (6), pan supporter ASSY (4), and wind shield ring (7).
8. Perform horizontal adjustment, and connect the AC adaptor.

TACJ/TACS-SH-e-1912 15
2.3 Replacing Components
2.3.1 Replacing the Front Glass ASSY (C8)
1. Extract the AC adaptor, and remove the pan (6), pan supporter ASSY (4), and
wind shield ring (7).
2. Remove the inside knob (C10), and remove the roof glass ASSY (C5) and side
glass ASSY (C6, C7).
* While supporting the front glass ASSY (C8), remove the screws.
3. Remove the screws on the back of the balance (truss M3 × 5 (4 screws)), and re-
move the rear cover (13).
4. Remove the two cover screws (B24) on the back side of the top of the balance,
remove the screw P4 M4 × 12 (2 screws), and remove the case roof (C3).
* After removing the case roof (C3), take care to prevent the front glass
ASSY (C8) from falling.
5. Remove the front glass ASSY (C8).
6. If the cushion (C13) adhering to the front pillar (C12) is damaged, replace it with
a new cushion (C13), (4 cushions).
Fig. 2-13
7. Follow this procedure in reverse to mount the new front glass ASSY (C8).
* Insert into the case roof (C3) groove so that the cushion adhesion side faces
toward the front.
Fig. 2-14

16 TACJ/TACS-SH-e-1912
2.3.2 Replacing the Side Glass ASSY (C6, C7)
1. Extract the AC adaptor, and remove the inside knob (C10).
2. Remove the side glass ASSY (C6, C7).
3. Insert the new side glass ASSY (C6, C7), and mount the knob (C10).
4. Open the side glass ASSY (C6, C7), and coat lubricant (OT1) on the upper and
lower glass edges (5 cm from the edge).
Fig. 2-15
2.3.3 Replacing the Roof Glass ASSY (C5)
1. Extract the AC adaptor, and remove the inside knob (C10).
2. Remove the roof glass ASSY (C5).
3. Insert the new roof glass ASSY (C5), and mount the knob (C10).
2.3.4 Replacing the Display Board ASSY (B2)
1. Use the procedures in "2.2 Inspecting the Balance Interior" to remove as far as
the case ASSY (3).
2. Remove the connector inserted into the display board ASSY (B2). (ACJ series: 4
locations, ACS series: 2 locations)
3. Loosen the screw P3 M3 × 8 (4 screws) fixing the display board ASSY (B2) in
place, and remove the display board ASSY (B2).
4. Use the screw P3 M3 × 8 (4 screws) to temporarily tighten the new display board
ASSY (B2).
5. Adjust the mounting position for the display board ASSY (B2). Align the left and
right directions to the edges of board mounting surfaces on the mount, display
board (B8). For the front-to-back direction, align the display board ASSY (B2) to
a pressed-forward position, and attach the screw P3 M3 × 8 (4 screws).

TACJ/TACS-SH-e-1912 17
*Align the display board ASSY (B2) height position to left and right.
Fig. 2-16
6. Assemble the balance in the reverse procedure to the steps 1) and 2).
2.3.5 Replacing the Power Board ASSY (B4)
1. Use the procedures in "2.2 Inspecting the Balance Interior" to remove as far as
the case ASSY (3).
2. Remove the connector inserted into the power board ASSY (B4). (1 location)
3. Loosen the bolt P3 M3 × 8 (4 bolts) fixing the power board ASSY (B4) in place,
and remove the power board ASSY (B4).
4. Use a bolt to temporarily fix the new power board ASSY (B4) in place.
5. Use the procedures in "2.2 Inspecting the Balance Interior" to assemble the case
ASSY (3).
6. Use the I/F board mounting jig (J6) to adjust and fix the position of the power
board ASSY (B4). With the centers of the two connectors, and of the jig ACJ for
board mounting (J7) holes, in aligned positions, adjust the board position so that
it comes to the farthest outside position.
Fig. 2-17
7. Mount the rear cover (13).

18 TACJ/TACS-SH-e-1912
2.3.6 Replacing the Analog Board ASSY (B3)
1. Use the procedures in "2.2 Inspecting the Balance Interior" to remove as far as
the unit cover (B5).
2. Insert the lever fixing pin (J1) into the lever fixing hole on the top of the OPF.
3. Remove the connector on the upper side of the board inserted into the analog
board ASSY (B3). (3 locations)
Fig. 2-18
4. Remove the connector inserted into the detector ASSY (U11). (1 location)
* When removing, use caution to ensure that it does not come into contact
with the lever ASSY (U7) and scratch the elastic support.
Fig. 2-19
5. Loosen the clamp, E-20-3C (B10) mounted to the base unit ASSY (2), and re-
move the wire.
Fig. 2-20

TACJ/TACS-SH-e-1912 19
6. Loosen the screw P4 M4 × 8 and flat washer M4 (2 locations) fixing the mount,
analog board (B11)
in place, and remove the mount, analog board (B11).
7. Loosen the screw P3 M3 × 8 (4 screws) fixing the analog board ASSY (B3) in
place, and remove the analog board ASSY (B3).
8. Remove the connector (for the coil) inserted into the analog board ASSY (B3).
9. Use the above procedure in reverse to mount the new analog board ASSY (B3).
2.3.7 Replacing the Weight Loader ASSY (27)
1. Use the procedures in "2.2 Inspecting the Balance Interior" to remove as far as
the unit cover (B5).
2. Loosen the screw P4 M4 × 8 (2 screws) and flat washer M5 (2 locations), remove
the weight stopper (W3), and remove the weight.
* When removing the weight (W4), be careful to avoid damaging the unit
ASSY (1). (Be careful to avoid letting the weight stopper (W3) rotating in
tandem and coming into contact with the pan supporter axis.)
* When performing re-assembly, be careful to avoid letting dust settle on
the weight (W4).
3. Loosen the screw P4 M4 × 8 (4 screws), and remove the weight loader ASSY
(27).
4. Use the above procedure in reverse to mount the new weight loader ASSY (27).
* Mount the weight loader ASSY (27) on cell width of the unit ASSY (1) in
the balance left and right directions.
* Be careful to avoid letting the weight loader mechanism come into con-
tact with the lever.
* When mounting, press the weight loader ASSY (27) forward for the
mounting position.
Fig. 2-21

20 TACJ/TACS-SH-e-1912
2.3.8 Replacing the Unit ASSY (1)
1. Use the procedures in "2.2 Inspecting the Balance Interior" to remove as far as
the unit cover (B5).
2. Loosen the screw P4 M4 × 8 (2 screws) and flat washer M5 (2 locations), remove
the weight stopper (W3), and remove the weight.
3. Insert the lever fixing pin (J1) into the lever fixing hole on the top of the OPF.
* Lift up on the lever ASSY (U7) to insert the pin. Proceed carefully to avoid
scratching the elastic support.
4. Remove the connector inserted into the detector ASSY (U11). (1 location)
* When removing, use caution to ensure that it does not come into contact
with the lever ASSY (U7) and scratch the elastic support.
5. Stand the back of the base ASSY (B1) on the floor, loosen the bolt P3 M5 × 12 (3
bolts) on the bottom of the base ASSY (B1), and remove the unit ASSY (1).
Fig. 2-22
6. After setting the new unit ASSY (1), use the bolt P3 M5 × 12 (3 bolts) on the bot-
tom of the base ASSY (B1) to temporarily fix the unit ASSY (1), then use the unit
ASSY positioning pin (J2) and plate (J8) to adjust the position, and tighten. (35
kgf—cm)
*When lifting up on the new unit ASSY (1), do not hold it by the parallel
guide and movable pillar part.
* When setting the unit ASSY positioning jig (J2), be careful to avoid dam-
aging the unit ASSY (1).
Fig. 2-23
7. See 2.3.7 to mount the weight loader ASSY (27).
* Mount the weight loader ASSY (27) on cell width of the unit ASSY (1) in
the balance left and right directions.
* Be careful to avoid letting the weight loader mechanism come into con-
tact with the lever.