OHAUS TROOPER User manual

Ohaus Corporation 19A Chapin Road, P.O. Box 2033, Pine Brook, NJ 07058 [phone]
TROOPER®SCALE &
TROOPER®COUNT SCALE
SERVICE MANUAL

The information contained in this manual is believed to be accurate at the time of publication,
but Ohaus Corporation assumes no liability arising from the use or misuse of this material.
Reproduction of this material is strictly prohibited.
Material in this manual is subject to change.
© Copyright 2004 Ohaus Corporation, all rights reserved.
® Registered trademark of Ohaus Corporation.
Trooper®Scale &
Trooper®Count Scale
TROOPER®SCALE
TROOPER COUNT®SCALE
SERVICE MANUAL

i
TABLE OF CONTENTS
CHAPTER 1 INTRODUCTION
Page
1. Introduction ...................................................................................................... 1-1
1.1 Service Facilities ................................................................................................. 1-1
1.2 Tools and Equipment .......................................................................................... 1-2
1.2.1 Standard Tools and Test Equipment............................................................ 1-2
1.2.2 Special Tools........................................................................................... 1-2
1.3 Calibration Masses Required ................................................................................ 1-2
1.4 Service Strategy .................................................................................................. 1-3
CHAPTER 2 DIAGNOSIS
2. Diagnosis ...................................................................................................... 2-1
2.1 Scale Setup and Examination ............................................................................... 2-1
2.2 Preliminary Checks ............................................................................................. 2-1
2.3 Troubleshooting Tables ....................................................................................... 2-1
2.4 Trooper Scale Diagrams ....................................................................................... 2-7
2.5 Trooper Scale Error Code Table.............................................................................. 2-8
2.6 Trooper Count Scale Diagram ............................................................................. 2-15
2.7 Trooper Count Scale Error Code Table .................................................................. 2-16
CHAPTER 3 REPAIR PROCEDURES
3.1 Repair Procedures ............................................................................................... 3-1
3.1 Replacing the Trooper Scale Membrane Switch ....................................................... 3-1
3.2 Replacing the Trooper Scale Main PC Board ........................................................... 3-2
3.3 Replacing the Trooper Scale Load Cell Assembly ..................................................... 3-4
3.4 Replacing the Trooper Count Scale Membrane Switch .............................................. 3-6
3.5 Replacing the Trooper Count Scale Main PC Board .................................................. 3-7
3.6 Replacing the Trooper Count Scale Display PC Board .............................................. 3-8
3.7 Replacing the Trooper Count Scale Load Cell Assembly............................................ 3-9
CHAPTER 4 TESTING
4.1 Testing ...................................................................................................... 4-1
4.1 Trooper Scale Operational Test.............................................................................. 4-1
4.1.1 Segment Display Test ............................................................................... 4-1
4.2 Trooper Count Scale Operational Test .................................................................... 4-1
4.2.1 Segment Display test ................................................................................ 4-1
4.3 Performance Tests............................................................................................... 4-2
4.3.1 Repeatability Test..................................................................................... 4-2
4.3.2 Off-Center Load Test ................................................................................. 4-4
4.3.3 Linearity Test ........................................................................................... 4-5
4.4 Trooper Scale Specifications ................................................................................. 4-6
4.5 Trooper Count Scale Specifications........................................................................ 4-6
4.6 Communication Test ........................................................................................... 4-7
4.6.1 Setting Trooper Scale Print Menu ................................................................ 4-7
4.6.2 Setting Trooper Count Scale Print Menu ....................................................... 4-7
4.6.3 Connecting the RS232 Interface ................................................................. 4-8
4.6.4 Print Test ................................................................................................ 4-9

ii
CHAPTER 5 PARTS LISTS
5. Parts Lists ...................................................................................................... 5-1
5.1 Trooper Scale/Trooper Count Scale Exploded View ................................................... 5-2
APPENDIX A CALIBRATION
A.1 Trooper Scale Linearity Calibration ........................................................................ A-1
A.2 Trooper Count Scale Linearity Calibration ............................................................... A-2
A.3 Linearity Calibration Weights................................................................................ A-4
APPENDIX B TROOPER COUNT SCALE TOOLS
B.1 Introduction ...................................................................................................... B-1
B.2 Installation ...................................................................................................... B-1
B.2.1 Minimum Requirements ............................................................................ B-1
B.2.2 Connecting the RS232 Interface ................................................................. B-1
B.2.3 Installing the Trooper Count Scale Tools Software Program ............................ B-1
B.2.4 Opening the Trooper Count Scale Tools Software Program ............................. B-1
B.3 Screen Operations ............................................................................................... B-2
B.3.1 Configuration (Config).............................................................................. B-2
B.3.2 Library .................................................................................................... B-4
B.3.3 Test Command ........................................................................................ B-7
B.3.4 Com Port ................................................................................................ B-8
B.4 Troubleshooting.................................................................................................. B-9
TABLE OF CONTENTS (Cont.)
Page

iii
TABLE OF CONTENTS (Cont.)
LIST OF TABLES
TABLE NO. TITLE PAGE
1-1 Calibration Masses............................................................................. 1-2
2-1 Trooper Scale - Will Not Turn on With AC Adapter .................................... 2-1
2-2 Trooper Scale - Will Not Turn on Using Batteries ..................................... 2-2
2-3 Trooper Scale - Does Not Respond to Front Panel Controls ....................... 2-3
2-4 Trooper Scale - No Display or Partial Display ......................................... 2-4
2-5 Trooper Scale - Cannot Calibrate........................................................... 2-4
2-6 Trooper Scale - Communications Failure ................................................ 2-6
2-7 Trooper Scale Error Codes .................................................................... 2-8
2-8 Trooper Count Scale - Will Not Turn on With AC Adapter .......................... 2-9
2-9 Trooper Count Scale - Will Not Turn on Using Batteries .......................... 2-10
2-10 Trooper Count Scale - Does Not Respond to Front Panel Controls ............ 2-11
2-11 Trooper Count Scale - No Display or Partial Display .............................. 2-12
2-12 Trooper Count Scale - Cannot Calibrate ............................................... 2-13
2-13 Trooper Count Scale - Communications Failure..................................... 2-14
2-14 Trooper Count Scale Error Codes ......................................................... 2-15
4-1 Trooper Scale Specifications ................................................................ 4-6
4-2 Trooper Count Scale Specifications ....................................................... 4-6
4-3 Trooper Scale RS232 Commands ......................................................... 4-8
4-4 Trooper Count Scale RS232 Commands ................................................ 4-9
5-1 Trooper Scale (TR) and Trooper Count Scale (TC)Parts List ...................... 5-3
A-1 Trooper Scale Linearity Weights .............................................................A-4
A-2 Trooper Count Scale Linearity Weights ....................................................A-4
LIST OF ILLUSTRATIONS
FIGURE NO. TITLE PAGE
2-1 Trooper Scale Interconnection Diagram.................................................. 2-7
2-2 Trooper Scale Membrane Switch Wiring Diagram .................................... 2-7
2-3 Trooper Count Scale Interconnection Diagram ...................................... 2-17
2-4 Trooper Count Scale Membrane Switch Wiring Diagram ......................... 2-18
3-1 Trooper Scale Connector Locations ....................................................... 3-2
3-2 Trooper Scale RS Connector and Loadcell Connector Wiring ..................... 3-3
3-3 Trooper Scale Component Locations ..................................................... 3-5
3-4 Trooper Count Scale Main PC Board Connector Locations ........................ 3-7
3-5 Trooper Count Scale RS Connector and Loadcell Connector Wiring ............ 3-8
3-6 Trooper Count Scale Component Locations .......................................... 3-10
4-1 Trooper Scale Segment Displays ........................................................... 4-1
4-2 Trooper Count Scale Segment Displays.................................................. 4-1
4-3 Standard Deviation Worksheet ............................................................. 4-3
4-4 Calculation of Standard Deviation ........................................................ 4-3

iv
4-5 Sample Calculation of Standard Deviation ............................................. 4-4
4-6 Off-Center Load Test Weight Locations .................................................. 4-4
4-7 RS232 Interface Pin Connections ......................................................... 4-8
5-1 Expoded View of Trooper Scale and Trooper Count Scale.......................... 5-2
LIST OF ILLUSTRATIONS (Cont.)
FIGURE NO. TITLE PAGE

1-1
CHAPTER 1 INTRODUCTION
1. INTRODUCTION
This service manual contains instructions for the repair and maintenance work to be performed by Ohaus
Dealers or Ohaus authorized service centers. Knowledge of the operation of the Scale is assumed.
Instruction manuals are included with this service manual. For complete information on operation, refer
to the Instruction Manual.
This manual covers maintenance on the following:
Trooper®Scales (capacities 3kg, 6kg, 15kg and 30kg.)
Trooper®Count Scales (capacities 3kg, 6kg, 15kg and 30kg.)
The contents of this manual are contained in five chapters and an Appendix with calibration information.
Chapter 1 Introduction - Contains information about service facilities, tools and test equipment, test
masses, and service strategy.
Chapter 2 Diagnosis - Contains information on problem verification, scale examination, preliminary
checks, troubleshooting tables, interconnection diagrams and wiring diagrams.
Chapter 3 Repair Procedures - Contains detailed repair procedures for all major components.
Chapter 4 Testing - Contains performance tests, specifications and communications testing procedures.
Chapter 5 Parts Lists - Contains exploded views of Trooper Scale and Trooper Count Scale identifying all
serviceable replacement components with associated parts lists.
Appendix A Calibration - Contains linearity calibration procedures for the Trooper Scale and Trooper
Count Scale.
Appendix B Trooper Count Scale Tools - Contains information on scale configuration, library data and
testing output commands from a computer.
1.1 SERVICE FACILITIES
The service area should be a stable environment.
The bench area should be clean and should contain an antistatic mat with a personnel grounding clip to
protect internal circuit boards. The ideal electrical power source for the scales should be a dedicated line
to avoid sudden fluctuations or voltage drops caused by external equipment drawing heavy current.
The service area for the scales should be away from direct sunlight, overhead heating or air conditioning
ducts, magnetic fields such as motors or large transformers or near vibrating sources such as machinery,
motors or vibrating equipment.
The power outlet should be grounded for safety. Sufficient space should be provided around the scale as
not to be affected by other equipment. This will ensure that the scale is operated under ideal conditions.

1-2
CHAPTER 1 INTRODUCTION
1.2 TOOLS AND EQUIPMENT
1.2.1 Standard Tools and Test Equipment
The service shop should contain the following equipment:
1. Digital Voltmeter (DVM).
2. Standard Electronics tool kit.
3. Desk magnifier on a stand.
4. Grounding mat and clip.
5. Flat Exacto® blades and holder.
1.2.2 Special Tools
To service the Ohaus Trooper Scale and Trooper Count Scale, the following equipment is
recommended:
1. A PC computer with a terminal program for communications.
2. Trooper Count Scale Tools- software program, Ohaus P/N 80500590.
3. RS-232 Cable - Ohaus P/N 80500433, IBM-PC 9 pin or standard null modem cable.
4. RS-232 Cable - Ohaus P/N 80500431, IBM - PC 25 Pin
5. Ohaus Printer Model SF42
6. Ohaus Printer Cable P/N 80500571
7. AC adapter, 120V, 60Hz (US) Ohaus P/N 80500435
8. AC adapter, 230V, 50Hz (EU) Ohaus P/N 80500436
9. AC adapter, 230V, 50Hz (UK) Ohaus P/N 80500437
10. AC adapter, 240V, 50 Hz (AU) Ohaus P/N 80500462
11. Load Cell Simulator
1.3 CALIBRATION MASSES REQUIRED
The masses required to test the Ohaus Trooper Scale and Trooper Count Scale must meet the requirements
of ASTM Class 4 or OIML F2. The mass values are listed in Table 1-1. Bolded values are default settings.
TABLE 1-1. CALIBRATION MASSES
Cal in kg: Cal in kg: Masses Totaling Masses Totaling
TC3RS TR3RS 1, 2, 3kg 2 & 3 kg
TC6RS TR6RS 2, 4, 6kg 4 & 6 kg
TC15RS TR15RS 5, 10, 15kg 10 & 15 kg
TC30RS TR30RS 10, 20, 30kg 20 & 30 kg
Cal in lb: Cal in lb: Span Cal choices Linearity Cal (fixed)
Masses Totaling Masses Totaling
TC3RS TR3RS 2, 4, 6 lb 4 & 6 lb
TC6RS TR6RS 5, 10, 15 lb 10 & 15 lb
TC15RS TR15RS 10, 20, 30 lb 20 & 30 lb
TC30RS TR30RS 20, 40, 60 lb 40 & 60 lb
TROOPER COUNT SCALE TROOPER SCALE Span Cal choices Linearity Cal (fixed)

1-3
CHAPTER 1 INTRODUCTION
1.4 SERVICE STRATEGY
The repair method for the Trooper Scale and Trooper Count Scale is the direct substitution of major
assemblies.
The Trooper Scale contains 3 major replaceable assemblies: Cover Assembly with Membrane Switch,
Load Cell Assembly with Frame and the Main PC Board with LCD.
The Trooper Count Scale contains 4 major replaceable assemblies: Cover Assembly with Membrane
Switch, Display PC Board with LCD, Load Cell Assembly with Frame and the Main PC Board.
This service manual contains sufficient information to isolate the problem, replace the component, test and
restore the Scale to original factory specifications.

1-4
CHAPTER 1 INTRODUCTION

2-1
CHAPTER 2 DIAGNOSIS
2. DIAGNOSIS
This section contains information needed to properly evaluate the reported problem and diagnose its cause.
2.1 SCALE SETUP AND EXAMINATION
Set up the scale according to the Instruction manual. Allow the scale to stabilize to room
temperature. Examine the scale for signs of corrosion or physical damage.
2.2 PRELIMINARY CHECKS
Power up the scale using the customer's ac adapter. In the case where the scale will not power up,
check the ac adapter. Observe and record the error codes and software revision. Record all menu
settings if possible as received.
2.3 TROUBLESHOOTING TABLES
Troubleshooting tables 2-1 through 2-14 identify actual types of problems that could be
encountered with the scale.
Trooper Scales are covered in Tables 2-1 through 2-7.
Trooper Count Scales are covered in Tables 2-8 through 2-14.
The troubleshooting tables refer to interconnection and wiring diagrams in this section to assist in locating
the problem.
SYMPTOM
Scale will not turn on with AC
adapter supplied
PROBABLE CAUSE
Adapter defective.
DC input connector at rear of
scale is defective.
Membrane Switch defective.
Main PC Board is defective.
REMEDY
Check the ac adapter voltage output.
The ac adapter output should measure
12-16 Volts dc. If voltage is low or
nonexistent, replace the ac adapter. If
OK, proceed.
Disconnect the ac adapter. Remove
the 6 screws from the bottom cover of
the scale, carefully remove the plat-
form, top cover and disconnect the
flexible cable from the Main PC Board.
See Figure 2-1.
Reconnect the ac adapter to the scale.
Check dc voltage at pins 1 and 4 of
connector J7 on the Main PC Board.
Should read between 12-16 Volts dc
(power off), 12-14 Volts dc (power
on). If voltage is not present, replace
the Main PC Board. If OK, proceed.
See Table 2-3.
If the scale fails to turn on with a new
Membrane Switch, the Main PC Board
is defective and should be replaced.
-> Repair Procedures 3.2.
TABLE 2-1 TROOPER SCALE - WILL NOT TURN ON WITH AC ADAPTER.

2-2
CHAPTER 2 DIAGNOSIS
SYMPTOM
Scale will not turn on with
new batteries installed.
PROBABLE CAUSE
Incorrect battery installation.
Wiring harness defective or
battery clips connection bro-
ken.
Membrane Switch defective.
Main PC Board is defective.
REMEDY
Check position of batteries.
Remove the 6 screws from the bottom
cover of the scale, carefully remove the
platform, top cover and remove the flex-
ible cable from the Main PC Board.
Check dc voltage at pins 1 and 3 of
connector J6 on the Main PC Board. See
Figure 2-1. Voltage should read ap-
proximately 9 Volts dc. If voltage is not
present at the connector, remove the bat-
teries and make a continuity test be-
tween each of the connectors in the bat-
tery box to connector J6, pins 1 and 3 on
the Main PC Board. Resistance should
be 0 ohms for the red lead and 0 ohms for
the black lead. If an open condition
exists, trace wiring and resolder or re-
place wiring as necessary. If OK, pro-
ceed.
See Table 2-3.
If the scale fails to turn on with a new
Membrane Switch, the Main PC Board is
defective and should be replaced.
-> Repair Procedures 3.2.
TABLE 2-2 TROOPER SCALE - WILL NOT TURN ON USING BATTERIES.

2-3
CHAPTER 2 DIAGNOSIS
SYMPTOM
Scale does not respond to front
panel controls.
NOTE:
Use a known good ac adapter
for this test.
PROBABLE CAUSE
Membrane Switch is defec-
tive.
REMEDY
1. Open the scale, remove six screws
from the bottom of the scale.
2. Refer to Figure 2-2. Using an Ohm-
meter,measurethe resistance between
pins 1 to all other pins on the mem-
brane switch cable, they should all
be open, then press each button and
check that the resistance is zero for
each button. If continuity is not
present, the membrane switch is de-
fective. Replace Membrane Switch
-> Repair Procedures 3.1.
or
Substitute with a good membrane
switch plugged into the Main PC Board
and press each button if they work,
the original Membrane Switch is de-
fective and should be replaced.
-> Repair Procedures 3.1.
3. If Membrane Switches are OK, re-
place Main PC Board. -> Repair
Procedures 3.2.
TABLE 2-3 TROOPER SCALE - DOES NOT RESPOND TO FRONT PANEL CONTROLS.

2-4
CHAPTER 2 DIAGNOSIS
SYMPTOM
Display is not on or partial
characters are displayed.
PROBABLE CAUSE
Main PC Board is defective.
REMEDY
The Main PC Board is replaced as a
whole assembly. Check procedures in
Table 2-1 first and verify that other prob-
lems do not exist.
Replace Main PC Board. -> Repair
Procedures 3.2.
TABLE 2-4 TROOPER SCALE - NO DISPLAY OR PARTIAL DISPLAY.
SYMPTOM
Scale can be turned on but will
not calibrate.
PROBABLE CAUSE
Incorrect weights.
LFT lock switch is in the
locked position and/or
The software lock menu is
set to ON (LCL On).
Load cell assembly defec-
tive.
REMEDY
Verify that proper weights are used.
Set LFT lock switch to unlocked posi-
tion and/or
Set the software lock menu to OFF
(LCLOFF), then refer to instruction
manual.
Remove the 6 screws from the bottom
cover of the scale. Carefully remove the
platform. Lift the top cover and lay
aside leaving the cables connected to
the Main PC Board.
With the scale plugged in and turned
on, measure voltage on terminals -EXE
and +EXE. The nominal voltage should
be 5 V dc. If the voltage is much lower,
disconnect the load cell from the PC
Board and measure again. If 5V dc is
present, the load cell may be shorted
and requires replacement. Continue,
see next page.
TABLE 2-5 TROOPER SCALE - CANNOT CALIBRATE.

2-5
CHAPTER 2 DIAGNOSIS
SYMPTOM
Scale can be turned on but will
not calibrate (Cont.).
PROBABLE CAUSE
Load Cell assembly defec-
tive.
Main PC Board defective.
REMEDY
With the platform in place and the scale
turned on, measure across pins -SIG
and +SIG on the PC Board. Typical no
load output from the Load Cell is -1.0
mv to + 1.0 mv. If the output exceeds
this value, replace the load cell.
If this measurement is within limits,
place a full load on the platform and
measure again. The difference between
zero and full load readings should be
as shown in the table below. If the
reading is out of this range, try replac-
ing the Load Cell. -> Repair Procedures
3.3. NOTE: Readings may differ from
table due to load cell tolerances.
Reassemble, the scale, perform tests in
Section 5 and verify operation.
If the above readings are within limits,
the Main PC Board is defective.
To check the Main PC Board if unsure
about the load cell, connect a known
good load cell or load cell simulator to
connector J4 as shown in Figure
2-1. Use an output of 0 mv/V for CAL
ZERO and 1 mv/V for span calibration.
If unable to calibrate, the Main PC
Board is defective. Replace Main PC
Board. -> Repair Procedures 3.2.
TABLE 2-5 TROOPER SCALE - CANNOT CALIBRATE (Cont.).
LOAD CELL OUTPUT READINGS
MODEL SPAN SIGNAL
TR3RS 4.0-5.0mv
TR6RS 3.5-4.5mv
TR15RS 4.5-5.5mv
TR30RS 6.5-8.3mv
NOTE: Span signal readings are approximate.
If readings are slightly above or below
these limits, the loadcell may still function properly.

2-6
CHAPTER 2 DIAGNOSIS
SYMPTOM
Communications cannot be
established with scale turned
on.
PROBABLE CAUSE
Communication cable is not
plugged in or the incorrect
cable is being used.
Improper settings in the Print
menu.
Main PC Board is defective.
REMEDY
Tighten connectors and use the proper
cable.
Ensure that the communications param-
eters of the scale and periphal device
match.
Replace Main PC Board. -> Repair
Procedures 3.2. Reassemble the scale.
Perform tests in Section 5 and verify
operation.
TABLE 2-6 TROOPER SCALE - COMMUNICATIONS FAILURE.

2-7
CHAPTER 2 DIAGNOSIS
Figure 2-1. Trooper Scale Interconnection Diagram.
MEMBRANE
SWITCH
Print
Units G/N/T Menu On/Zero
Off Tare
Figure 2-2. Trooper Scale Membrane Switch Wiring Diagram.
2.4 TROOPER SCALE DIAGRAMS
Load Cell
9
8
6
7
1
2
3
4
5
GND
TXD
RXD -SIG
+SIG
+EXE
-EXE
CGND
Yellow
1
J4
5
4
3
2
1
Membrane Switch
Red
3
4
White
5
6
Orange
Green
7
1
White
2
3
J10
Black
2
31
Black
Red
J7
1
2
Red
J6
4
Main PC Board
Red
Harness,PWR/COM
RS232
1
2
3
4
5
3
Black
J1
Adaptor Input
Battery Holder
2
J5A
TARE
PRINT UNITS
ON/ZERO & OFF
COMM
G/N/T & MENU
NOT USED

2-8
CHAPTER 2 DIAGNOSIS
2.5 TROOPER SCALE ERROR CODE TABLE
The Trooper Scale is equipped with software which will display an error condition when it occurs. Review
the listed codes and follow instructions to correct the problem.
TABLE 2-7. TROOPER SCALE ERROR CODES
ERROR CODE
LoBat
Error 1
Error 2
Error 7
Error 14
Error 21
CAUSE
Batteries are weak.
The load on the platform ex-
ceeds the rated capacity of
the scale (overload condi-
tion).
Underload condition. The
load cell signal is more than
9 divisions below zero.
EEPROM data incorrect.
When ZERO button is
pressed, the load on the pan
exceeds zero % menu set-
ting. Could be caused by a
load on the pan.
At power up, the load cell
signal is outside the allow-
able limit.
Checksum error.
REMEDY
Replace batteries.
Remove excess load.
Check load cell connections.
Refer to the Troubleshooting Tables.
Press the ON/ZERO Off button. If the
problem persists, refer to the trouble-
shooting section to check the load cell
assembly.
Turn scale on and off and on again. If
error 7 remains, replace the Main PC
board. -> Repair Procedures 3.2.
Enter the Setup Menu and set the zero %
to a higher setting. (See Instruction
Manual.)
Perform a linearity calibration. If this
fails, substitute the load cell assembly
and perform the linearity calibration
again. Refer to Table 2-5. If the substi-
tute load cell does not correct the condi-
tion, re-install the original load cell and
replace the Main PC board. ->Repair
Procedures3.2
Replace the load cell-> Repair Proce-
dures 3.3 and or Main PC board as
required ->Repair Procedures3.2
Recalibrate and check.