OHAUS TROOPER SCALE User manual

Ohaus CorporationOhaus Corporation
Ohaus CorporationOhaus Corporation
Ohaus Corporation
19A Chapin Road
P.O. Box 2033
Pine Brook, NJ 07058-2033 USA
www.ohaus.com
OhausCorporation19AChapinRoad,P.O.Box2033,PineBrook,NJ07058-2033(973)377-9000
TROOPER SCALE
SERVICE MANUAL

The information contained in this manual is believed to be accurate at the time of publication, but
OhausCorporationassumesnoliabilityarisingfromtheuseormisuseofthismaterial. Reproduc-
tion of this material is strictly prohibited.
Material in this manual is subject to change.
©Copyright 2001Ohaus Corporation,all rightsreserved.
® Registered trademark of Ohaus Corporation.
SERVICE MANUAL
Trooper Scale
Ohaus CorporationOhaus Corporation
Ohaus CorporationOhaus Corporation
Ohaus Corporation
19A Chapin Road
P.O. Box 2033
Pine Brook, NJ 07058-2033 USA
www.ohaus.com

i
TABLE OF CONTENTS
CHAPTER 1 INTRODUCTION
1.1 Overview of Controls and Display Functions ..........................................1-1
1.2 Introduction ..........................................................................................1-2
1.3 Service Facilities ....................................................................................1-2
1.4 Tools and Test Equipment Required ......................................................1-3
1.4.1 Special Tools..................................................................................1-3
1.4.2 Standard Tools and Test Equipment ..............................................1-3
1.5 Test Masses Required............................................................................1-3
1.6 Specifications .........................................................................................1-4
CHAPTER 2 THEORY OF OPERATION
2.1 Trooper Theory of Operation...................................................................2-1
2.2 Loadcell Theory ......................................................................................2-1
2.3 Printed Circuit Board Theory...................................................................2-1
2.3.1 Power Supply Circuit ......................................................................2-1
2.3.2 Power Monitor Circuit .....................................................................2-1
2.3.3 Microprocessor ...............................................................................2-2
2.3.4 MELSI ..........................................................................................2-2
2.3.5 MemoryStorage..............................................................................2-2
2.3.6 LCD Display Information.................................................................2-2
2.3.7 Display On/Off.................................................................................2-2
2.3.8 A/D Converter .................................................................................2-2
2.3.9 Load Cell Excitation Voltage ..........................................................2-2
2.3.10 RS232 Operation............................................................................2-2
CHAPTER 3 TROUBLESHOOTING
3.1 Troubleshooting......................................................................................3-1
3.2 Diagnostic Guide ....................................................................................3-1
3.2.1 Diagnosis........................................................................................3-1
3.3 Error Codes ..........................................................................................3-3
CHAPTER 4 MAINTENANCE PROCEDURES
4.1 Preventive Maintenance .........................................................................4-1
4.1.1 Preventive Maintenance Checklist..................................................4-1
4.2 Testing. ..........................................................................................4-1
4.2.1 Operational Test .............................................................................4-1
4.2.1.1 Segment Display Test .......................................................4-1
4.2.2 MenuStructure................................................................................4-2
4.2.3 Trooper Switch Functions ...............................................................4-3
4.2.4 Trooper Scale Menu Operation.......................................................4-3
4.2.4.1 How to Enter the Menus ....................................................4-3
4.2.4.2 How to Select a Specific Menu..........................................4-3
4.2.4.3 How to Enter an Individual Menu.......................................4-4
4.2.4.4 How to Enter an Individual Menu Item...............................4-4
4.2.4.5 How to Save and Store an Individual Menu Item...............4-4
Page

ii
4.2.4.6 How to Quit the Menus............................................................................4-4
4.2.5 Calibration ......................................................................................4-4
4.2.6 Legal for Trade (LFT) Operation and LFT Sealing..........................4-9
4.2.7 PerformanceTests........................................................................4-10
4.2.7.1 Repeatability Test ...........................................................4-10
4.2.7.2 Off-CenterLoadTest .......................................................4-11
4.2.7.3 Linearity Test...................................................................4-11
4.2.8 RS232 Interface Test ....................................................................4-13
4.2.8.1 Connecting the RS232 Interface .....................................4-13
4.2.9 Print Test ......................................................................................4-14
4.3 Repair Procedures .............................................................................4-15
4.3.1 Replacing the Keypad Membrane ................................................4-15
4.3.2 Replacing the PC Board ...............................................................4-16
4.3.3 Replacing the Spider Assembly (Loadcell)...................................4-18
CHAPTER 5 DRAWINGS AND PARTS LISTS
5.1 Drawings and Parts Lists.........................................................................5-1
5.1.1 Trooper Exploded View ..................................................................5-2
TABLE OF CONTENTS (Cont.)
CHAPTER 4 MAINTENANCE PROCEDURES (Cont.) Page

iii
TABLE OF CONTENTS (Cont.)
LIST OF TABLES
TABLE NO. TITLE PAGE NO.
1-1 Trooper Calibration Masses kg..........................................................1-3
1-2 Trooper Model Specifications............................................................1-4
1-3 Trooper General Specifications.........................................................1-4
3-1 Diagnostic Guide...............................................................................3-2
3-2 Error Codes .......................................................................................3-3
4-1 Calibration Masses............................................................................4-5
4-2 Types of performance Tests ............................................................4-10
4-3 Linearity Test Masses......................................................................4-11
4-4 RS232 Commands..........................................................................4-14
5-1 Trooper Parts List ..............................................................................5-3
LIST OF ILLUSTRATIONS
FIGURE NO. TITLE PAGE NO.
2-1 Trooper Block Diagram .....................................................................2-3
4-1 Segment Displays .............................................................................4-1
4-2 Trooper Scale Menu..........................................................................4-2
4-3 Lock Switch Location.........................................................................4-9
4-4 Sealing the Scale with a Lead Seal...................................................4-9
4-5 Sealing the Scale with a Paper Seal .................................................4-9
4-6 Off-Center Load Test mass Locations..............................................4-11
4-7 RS232 Interface Pin Connections ...................................................4-13
4-8 Connector Locations .......................................................................4-16
4-9 RS Connector and Loadcell Connector Wiring................................4-17
4-10 Trooper Component Locations ........................................................4-19
5-1 Exploded View of Trooper Scale.......................................................5-2
5-2 Trooper Scale Interconnection Diagram............................................5-4
5-3 Keypad Wiring Diagram ....................................................................5-4

iv

1-1
CHAPTER 1 INTRODUCTION
lb
kg
oz
BAT
*
No. Designation Function
1 Display LCD display, indicates weight, modes and setup information.
2 CenterofZero LCD indicator prompt, indicates center of zero when within +/- 0.25d.
3 Gross LCDindicator prompt, indicatesgrossweight.
4 Net LCDindicator promptindicatesnet weight.
5 Tare LCDindicatorpromptindicatestareweight.
6 ON/ZERO/OFFbutton Turns Scale on or off. Secondary use, provides zero function.
7 Print/Unitsbutton Short press, prints data which is displayed on the Scale.
Longpress, changes unit of measure. Longer press, enters countingmode.
When in menus, each press advances horizontally through the menus.
Finalizes a menu selection.
8 Tarebutton Whenpressed,enterstarevalue into memory.
9 G/N/T/Menubutton Recalls Gross/Net/Tare. Long press allows entry into menus. When in
menus,advancesthroughindividual menu items.
10 kg LCD indicator, when lit, indicates weight in kilograms.
g LCD indicator, when lit, indicates weight in grams.
11 lb LCD indicator, when lit, indicates weight in pounds.
12 oz LCD indicator, when lit, indicates weight in ounces.
13 * Stability indicator, when lit, indicates stable weight.
1.11.1
1.11.1
1.1 OVERVIEW OF CONTROLS AND DISPLAY FUNCTIONSOVERVIEW OF CONTROLS AND DISPLAY FUNCTIONS
OVERVIEW OF CONTROLS AND DISPLAY FUNCTIONSOVERVIEW OF CONTROLS AND DISPLAY FUNCTIONS
OVERVIEW OF CONTROLS AND DISPLAY FUNCTIONS
1
2
3 4568
9
10
7
11
13 12

1-2
CHAPTER 1 INTRODUCTION
DO NOT SERVICE the scale:
• Next to open windows or doors causing drafts or rapid temperature changes.
• Near air conditioning or heat vents.
• Near vibrating, rotating or reciprocating equipment.
• Near magnetic fields or equipment that generates magnetic fields.
• On an unlevel work surface.
• Allow sufficient space around the instrument for ease of operation and keep away from radiating
heat sources.
1.2 INTRODUCTION
This service manual contains instructions for the repair and maintenance work to be performed by
service engineers on the Trooper Scales. It is assumed that the reader is familiar with the operation
of the Scale and can refer to the relevant operating instructions when necessary.
This manual covers maintenance on the following:
Trooper Scales (capacities 3kg, 6kg, 15kg and 30kg.)
The contents of this manual is contained in five chapters.
Chapter 1 Introduction - Contains information regarding service facilities, tools and test equipment,
test masses, and specifications.
Chapter 2 Theory of Operation - Contains a basic information on circuit and loadcell operation.
Chapter 3 Troubleshooting - Contains a diagnosis/diagnostics chart and error code table.
Chapter 4 Maintenance Procedures - Contains preventive maintenance procedures, performance
tests and adjustments, repair procedures, service mode procedures, and calibration procedures.
Chapter 5 Drawings and Parts List - Contains exploded view of Trooper Scale identifying all
serviceable replacement components with parts list.
Before servicing the scale, you should be familiar with the Instruction Manual which is packed with
every Trooper Scale.
1.3 SERVICE FACILITIES
To service the Ohaus Trooper Scale, the service area should meet the following requirements:

1-3
CHAPTER 1 INTRODUCTION
1.4 TOOLS AND TEST EQUIPMENT REQUIRED
In order to properly service the Ohaus Trooper Scales, a standard electronic tool kit is required. No
special tools and test items are required.
1.4.1 Special Tools
None required.
1.4.2 Standard Tools and Test Equipment
1. Digital Voltmeter(DVM)-Input impedanceofatleast10 megohmsinthe1 Volt dcposition.
2. Standard Electronics tool kit
1.5 TEST MASSES REQUIRED
The masses required to test the Ohaus Trooper Scales must meet the requirements of ASTM
Class 4 Tolerance. The mass values are listed in Table 1-1.
TABLE 1-1. TROOPER CALIBRATION MASSES
Cal in kg: Span cal choices Linearity cal (fixed)
TR3RS 1, 2, 3kg 2 & 3 kg
TR6RS 2, 4, 6kg 4 & 6 kg
TR15RS 5, 10, 15kg 10 & 15 kg
TR30RS 10, 20, 30kg 20 & 30 kg
Cal in lb: Span cal choices Linearitycal (fixed)
TR3RS 2, 4, 6 lb 4 & 6 lb
TR6RS 5, 10, 15 lb 10 & 15 lb
TR15RS 10, 20, 30 lb 20 & 30 lb
TR30RS 20, 40, 60 lb 40 & 60 lb

1-4
CHAPTER 1 INTRODUCTION
1.6 SPECIFICATIONS
Completespecificatonsforthe OhausTrooperScalesarelistedinTables1-2and1-3. Whenascale
has been serviced, it must meet the specifications listed in the tables. Before servicing the scale,
determine what specifications are not met.
TABLE 1-2. TROOPER MODEL SPECIFICATIONS
General Specifications
Platform Size(w x d)(in/cm) 13.5 X 9" / 34 X 23
ScaleDimensions (wx dxh) (in/cm) 13.5 X 14.5 X 4.5 / 34.3 X 36.8 X 11.4
ShippingDimensions (wxd xh) (in/cm) 17 X 17 X 8.5 / 42.2 X 42.2 X 21.6
Weight(lb/kg) 8.6 / 3.9
ResolutionNTEP 1:3000
ResolutionMaximum 6,000 - 7,500 depending on model
Stabilization time 1-4secondsdepending uponfilterselection
Keyboard 4functionmembraneswitches
Weighingunits lb, kg,g,oz
Display BacklitLCD,25.4mm, 1"
Power AC Adapter or 6 alkaline C-type batteries
TypicalBatteryLife Up to 100 hours
SpanCalibration 1/3 tofullcapacity
LinearityCalibration(3-pointcalibration) Allmodels
Auto-zerotracking Off,0.5,1, or3 divisions
Construction Stainlesssteelweighingpan,ABSplastichousing
Protection IP43
Operating Temperature 14°F to 104°F / -10°C to 40°C
Storage Temperature -40°F to 140°F / -20°C to 60°C
Standard Models TR3RS TR6RS TR15RS TR30RS
DefaultCapacityXReadability (lb)* 6lbX0.001lb 15lbX0.002lb 30lbX0.005lb 60lbX0.01lb
DefaultCapacityXReadability (kg)* 3kgX0.0005kg 6kgX0.001kg 15kgX0.002kg 30kgX0.005kg
DefaultCapacityXReadability (g) 3000gX0.5g 6000gX 1g 15000gX2g 30000gX5g
DefaultCapacityXReadability (oz) 48ozX0.02oz 240ozX0.05oz 480ozX0.1oz 960ozX0.2oz
NTEPCapacityXReadability (lb) 6lbX0.002lb 15lbX0.005lb 30lbX0.01lb 60lbX0.02lb
NTEPCapacityX Readability (kg) 3kgX0.001kg 6kgX0.002kg 15kgX0.005kg 30kgX0.01kg
NTEP CapacityXReadability (g) 3000gX 1g 6000gX 2g 15000gX5g 30000gX10g
NTEPCapacityXReadability (oz) 48ozX0.05oz 240ozX0.1oz 480ozX0.2oz 960ozX0.5oz
Linearity (g) +0.5g +1.0g +2.0g +5.0g
Item Number TR3RS-2E0 TR6RS-2E0 TR15RS-2E0 TR30RS-2E0
NOTE: All Trooper models meet the requirements of Approval Agencies: UL, FCC, CSA, CE. NTEP approval.
*Defaultcapacityandreadabilityaredependentoncalibrationunitselected.Thetableaboveassumesthatthecalibration
unit is the same as the displayed unit listed.
TABLE 1-3. TROOPER GENERAL SPECIFICATIONS

2-1
CHAPTER 2 THEORY OF OPERATION
2.2 LOADCELL THEORY
TheLoadcellassemblyusedinTrooperbalancesispartofaSpiderAssembly. TheSpiderAssembly
consists of two spider shaped brackets in which the Loadcell is mounted in between in a sandwich
fashion. The Spider Assembly holds the Loadcell in proper alignment with preadjusted down-stop
screwswhicharelocktited. ThebottomhalfoftheSpiderAssemblyismountedtothebaseofthescale.
The upper half of the Spider Assembly forms the sub-platform for the scale. The platform assembly
is mounted directly to this. Loadcells may not be ordered as a replacement part since they are part
of the Spider Assembly.
Forelectricalcomponents,refertoschematicdiagramFigure5-2. Formechanicalcomponents,refer
toFigure5-1. OnebasictypeofLoadcellisusedintheTrooperbalances. TheLoadcellcontainsfour
Strain Gauges in a full bridge configuration. The full bridge has two Strain Gauges mounted on top
of the Transducer and two mounted on the bottom. A temperature compensation sensor is also
mounted on the top of the Loadcell.
The Loadcell consists of an aluminum beam with 4 Strain Gauges bonded at the hinged areas
(thinnest part of the beam). Two of the Strain Gauges are located on top of the beam and two on the
bottom. These4electricalstraingaugesarewiredtoformaWheatstonebridge. Whenaloadisplaced
onthebeam,itbendsatthehingedareas. ThebendingchangestheresistanceoftheStrainGauges
andtheresultingresistance output fromtheWheatstonebridge is proportionaltotheload. SixDown
Stop screws which are part of the upper Spider Assembly engages and limits the external load at
slightly over full load capacity and limits the bending of the beam, preventing damage due to
overloading. The Spider Assembly does not contain up-stop screws which protects the Transducer
assembly from exceeding maximum upward movement.
2.3 PRINTED CIRCUIT BOARD THEORY (See figure 2-1)
2.3.1 Power Supply Circuit U12
Power to the scale is supplied by a 9 V dc, 500mA Power Adapter to connector J7 or by 6 "C" size
Alkaline batteries. Power is regulated through U12 (3-terminal positive voltage regulator) to output
a regulated +5 V dc which supplies the board.
2.3.2 Power Monitor Circuit U9
Battery voltage is monitored by a power monitor circuit U9. When the battery voltage goes low to a
presetpoint,aresetsignal(LowBat)issentfromthe powermonitorcircuit tothemicroprocessor U7.
The microprocessor activates the display which indicates a low battery voltage condition.
2.1 TROOPER THEORY OF OPERATION
This chapter contains information on the basic theory of operation of the Loadcell and scale circuit
descriptions of the printed circuit board. An exploded view drawing is included in Chapter 5 which
identifiesallservicablecomponents ofthescale. Thedescriptions in thismanualreferto thenameof
the components identified in the exploded view drawing.

2-2
CHAPTER 2 THEORY OF OPERATION
2.3.3 Microprocessor U7
The microprocessor U7 contains a built in RAM, ROM and an LCD driver. Crystal Y1 operates at a
frequencyofapproximately4.00MHzandisusedtocontrolthefrequencyofthemicroprocessor. The
microprocessor provides serial data to the LCD display as well as parameter storage to EEPROM
U11. A TTL level signal is also provided to U1 (Max 202) for RS232 communications.
2.3.4 MELSI U8
TheMELSI,U8 isadigitalcontrollerused inconjunctionwiththe A/DConverter. Itprovidesall digital
functions required to run two independent A/D channels. The oscillator of the MELSI works with an
external crystal (Y2) which operates at a frequency of 11.0592MHz.
2.3.5 Memory Storage
TheEEPROMU11istheusermemorystoragedevicefortheindicator. Itcontains1024bitsofmemory
andstoresthecalibrationdataandtheselectedunitswhichareenabledanddisabled. Whenthescale
is turned off, all previous settings are retained.
2.3.6 LCD Display Information
The display information for the LCD comes directly from microprocessor U7 and is decoded with it's
internalcircuits. TheLCD isbacklitbypanel BL1anddrivercircuitry BL2operatedfrom BKLITsignal
from microprocessor U7.
2.3.7 Display ON/OFF
TheunitcontainsanON/OFFbutton. Thereisapower-savemodeinthesoftware. Whenthisfeature
is enabled, the scale will automatically turn off after 5 minutes after last keypad operation.
2.3.8 A/D Converter
TheA/Dconvertertakestheanaloginputvoltagefromtheloadcellsandproducesadigitaloutputcode
which represents the analog input. This is derived through U3, U4 and U5 circuitry. The SEN line is
to compensate for temperature influence. Two jumpers Jump1 and Jump 2 may short the SEN and
EXC for a four wire system.
2.3.9 Load Cell Excitation Voltage
A six (6) wire interface for the analog load cells is provided at J4 located on the PC board. Excitation
voltage for the load cells is +5 Vdc.
2.3.10 RS232 Operation
The RS232 half-duplex operation is controlled by the microcontroller U1, MAX 202. Signals
supportedareRXD,TXDandGND. Thereisnohandshakeinterface. Theserialportmayreceivethe
external Tare, Zero and Print command in ASCII code.
2.3 PRINTED CIRCUIT BOARD THEORY (Cont.)

2-3
CHAPTER 2 THEORY OF OPERATION
Figure 2-1. Trooper Block Diagram.
MICROPROCESSOR
MFG
W1
CAL
GND
S1
GND
C1
C2
J5A
2
1
KEYBOARD
KON/OFF
C3
5
4
INPUT
3
V-
V+
V-
V+
INPUT
ADAPTER
INPUT
BATTERY
J7
J6
1
2
4
3
3
2
1
RST-
MCE-
SKM
+5V/BATTERY
MONITOR
VOLTAGE
+VINB
RST-
MONITOR
+5V/BATTERY
VOLTAGE
JUMP2
JUMP1
1
2
3
4
5
7
6
INPUT
ANALOG L/C
J4
-SEN
-EXC
-SIG
MSCLK
MCE-
MSDI
MSDO
SKM
A/D
+EXC
CGND
+SIG
+SEN
CONVERTER
MFG. TEST
RS232 OUTPUT
5
4
LOWBAT
TXD
RXD
+5V/DC
GND
LOWBAT
J1
1
2
3
EEDI
EEDO
EECE
EECK
EEPROM
(1024BIT)
& BEEPER
BUZZER
BEEPER DRIVER
1
2
3
J10
GND
TXD1
RXD1
RXD
TXD
RS232 DRIVER
BKLIT
BACK LIGHT
DRIVER
& EL PANEL
LCD DISPLAY
SEG15
COM1
SEG1
COM4
U1
U11
BL2 BL1
U3, U4, U5, U8
U9
U7
2.3 PRINTED CIRCUIT BOARD THEORY (Cont.)

2-4
CHAPTER 2 THEORY OF OPERATION

3-1
CHAPTER 3 TROUBLESHOOTING
3.1 TROUBLESHOOTING
This section of the manual specifies problem areas of the scale which can occur. Information is
containedtoisolatespecificproblemsusingTable3-1,DiagnosticGuide,andTable3-2,ErrorCodes.
Followalldirectionsstepbystep. Makecertainthattheworkareaiscleanandusecarewhenhandling
components of the scale.
3.2 DIAGNOSTIC GUIDE
Table 3-1 is a diagnostic guide designed to help locate the problem area quickly and easily. To use
thetable,firstlocatethesymptomthatyouareobserving. Followthe symptomcolumnandreviewthe
probable cause column and remedy column. The probable causes are listed with the most common
causefirst. Ifthefirstremedydoesnotfixtheproblem,proceedontothenextremedy. Beforeattempting
to repair the scale, read all chapters of this manual to familiarize yourself with the scale components
and operation. Do not attempt repairs unless you fully understand the operation of the scale.
3.2.1 Diagnosis
1. Isolate and identify the symptom.
2. Refer to Table 3-1 Diagnostic guide and locate the symptom.
3. Follow the suggested remedies in the order that they appear.
4. Perform the indicated checks, or see the appropriate section of the manual.
5. Repair or replace the defective section of the scale.
NOTE:
If more than one symptom is observed, it is necessary to
approach one area at a time, and also remember, that the
symptoms may be interrelated.
In the event that erratic or fluctuating weight readings are observed, it is necessary to isolate the
problem to either the mechanical area or the electronic area of the scale.
If a problem arises that is not covered in this manual, contact:
Ohaus Corporation
19A Chapin Road
P.O. Box 2033
Pine Brook, NJ 07058-2033 USA
Tel: [phone]
Fax: [phone]
In the United States call toll free, 800-526-0659 between 8:00 a.m. and 6:00 p.m. EST.

3-2
CHAPTER 3 TROUBLESHOOTING
TABLE 3-1. DIAGNOSTIC GUIDE
SYMPTOM
Unit will not turn on.
CannotzeroScale,orwillnot
zero when turned on.
Center of Zero display indi-
cator erratic or does not ap-
pear with no load on scale
platform.
Cannot display weight in de-
sired weighing unit.
REMEDY
Check power cord connec-
tions.
Makesureadapterconnec-
tor is plugged all the way
into the Scale.
Check battery connector.
Checkorientationofthebat-
teries.
Replace batteries.
Check functions of mem-
brane switch.
Remove load on scale to
less than entered zero %.
Change allowable zero %
in ZERO parameter of
Setup menu.
Normaloperationwhenthis
feature is disabled.
Remove disturbances or
reduce motion.
Increase AZT level in read-
outmenu.
Increase averaging level in
readout menu.
Enable desired unit in
Readout menu.
Conversion too large (typi-
cally in g).
PROBABLE CAUSE(S)
Adapternotpluggedinorprop-
erly connected.
Batteries dead or not properly
installed.
Membrane switch failure.
Load on scale exceeds allow-
able zero % entered in ZERO
parameter of Setup menu.
RetainZeroDataisenabledin
scale menu.
Scale platform motion or dis-
turbances exceed center of
zero criteria.
Desired unit not set to ON in
Read menu.

3-3
CHAPTER 3 TROUBLESHOOTING
RS232 not working.
Unable to calibrate unit.
RS232 communication param-
eters set up incorrectly.
Improper or loose cable connec-
tions.
SoftwareLockoutswitchsettoON
and Lock Switch on the circuit
board set to open position.
Incorrect value for calibration
mass.
Verify communication pa-
rameters.
Check cable connections.
Set LCL to OFF in the
LocSWmenu,andsetLock
Switch on the circuit board
to ON position.
Use correct calibration
mass.
SYMPTOM PROBABLE CAUSE(S) REMEDY
TABLE 3-1. DIAGNOSTIC GUIDE (Cont.)
3.3 ERROR CODES
This scale is equipped with software which will display an error condition when it occurs. When a
problem occurs using the scale, the display will indicate an error code. Review the listed codes and
follow instructions to correct the problem. Table 3-2 Error Codes, describes the various error codes
which can appear on the display and specifies the probable reason and remedy.
TABLE 3-2. ERROR CODES
Indication Problem
LoBat Isindicatedwhenbatteriesareweak. Approximately20minutesofoperatingtime
remain. Replace batteries as soon as possible.
Error 1 Indicates an overload condition. Remove overload condition.
Error 2 Indicates an underload condition.
Error 7 EEPROM data incorrect. Check scale settings.
Error 14 Zero exceeds ZERO% and cannot be zeroed.
Error 21 Calibration data does not match current full scale, Grad and Cal Point settings.
Settings must be restored or the Scale must be recalibrated using the current
settings.

3-4
CHAPTER 3 TROUBLESHOOTING