OHAUS VALOR 4000 User manual

SERVICE MANUAL
VALOR™4000
VALOR™2000
Ohaus Corporation, 7 Campus Drive, Suite 310, Parsippany, NJ 07054 [phone]

SERVICE MANUAL
VALOR ™4000
VALOR ™2000
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.
30072404 © Copyright 2012 Ohaus Corporation, all rights reserved.
TM Registered trademark of Ohaus Corporation.

TABLE OF CONTENTS
Ohaus Corporation www.ohaus.com i Valor™2000/4000 Series Service Manual
Page No.
CHAPTER 1 GETTING STARTED
1.1 Introduction..............................................................................................................1-1
1.2 Service Facilities......................................................................................................1-1
1.3 Tools and Test Equipment Required........................................................................1-1
1.4 Specifications –Valor 4000......................................................................................1-2
1.5 Specifications –Valor 2000......................................................................................1-2
1.6 Scale Operation Valor 4000.....................................................................................1-3
1.6.1 Overview of the Controls...................................................................................1-3
1.6.2 Power On/Off....................................................................................................1-4
1.6.3 Menu Setup ......................................................................................................1-5
1.6.4 Menu Navigation...............................................................................................1-5
1.7 Scale Operation Valor 2000.....................................................................................1-6
1.7.1 Overview of the Controls...................................................................................1-6
1.7.2 Power On/Off....................................................................................................1-7
1.7.3 Menu Setup ......................................................................................................1-8
1.7.4 Menu Navigation...............................................................................................1-8
1.8 Legal For Trade .......................................................................................................1-9
1.8.1 Settings.............................................................................................................1-9
1.8.2 Verification........................................................................................................1-9
1.8.3 Sealing..............................................................................................................1-9
CHAPTER 2 TROUBLESHOOTING
2.1 Troubleshooting.......................................................................................................2-1
2.2 Diagnostic Guide......................................................................................................2-1
2.2.1 Diagnosis..........................................................................................................2-1
2.2.2 Checking Load Cells for Trouble.......................................................................2-2
2.2.3 Testing the Printed Circuit Board (PCB)............................................................2-4
2.2.4 Diagnostic Guide...............................................................................................2-6
CHAPTER 3 MAINTENANCE PROCEDURES
3.1 Preventive Maintenance...........................................................................................3-1
3.1.1 Preventive Maintenance Checklist....................................................................3-1
3.2 Service Strategy.......................................................................................................3-1
3.3 Opening the Scale....................................................................................................3-1
3.2.1 Separating the Top and Bottom Housings.........................................................3-2
3.4 Removing/Replacing the Main Printed Circuit Board (PCB) .....................................3-3
3.5 Removing/Replacing the Load Cell..........................................................................3-4
3.6 Setting the Overload Stops ......................................................................................3-5
3.7 Removing/Replacing the Rechargeable Battery.......................................................3-7
3.8 Replacing the Function Label...................................................................................3-7

TABLE OF CONTENTS
Valor™2000/4000 Series Service Manual ii Ohaus Corporation www.ohaus.com
CHAPTER 4 TESTING
4.1. Testing.....................................................................................................................4-1
4.1.1 Test Masses Required......................................................................................4-1
4.2 Operational Test ......................................................................................................4-1
4.3 Segment Display Test..............................................................................................4-1
4.4. Performance Tests...................................................................................................4-2
4.4.1 Precision Test...................................................................................................4-2
4.4.2 Repeatability Test.............................................................................................4-3
4.4.3 Linearity Test....................................................................................................4-5
4.4.4 Off-Center Load Test........................................................................................4-5
4.4.5 Adjusting Off Center Load.................................................................................4-6
CHAPTER 5 DRAWINGS AND PARTS LISTS
5-1 Valor 4000PW Scale: Housing & Internal Parts........................................................5-2
5-2 Valor 4000XW Scale: Housing & Internal Parts........................................................5-4
5-3 Valor 2000PW Scale: Housing & Internal Parts........................................................5-6
5-4 Valor 2000XW Scale: Housing & Internal Parts........................................................5-8
Appendix A STANDARD CALIBRATION
A.1 Calibration...............................................................................................................A-1
A.2 Setup and Calibration..............................................................................................A-2
Appendix B SERVICE CALIBRATION
B.1 Service Menu Structure...........................................................................................B-1
B.2 Entering the Service Menu......................................................................................B-1
B.3 Ramp Menu ............................................................................................................B-2
B.4 Service Linearity Calibration....................................................................................B-2
B.5 Service Span Calibration.........................................................................................B-3
B.6 Capacity Menu........................................................................................................B-3
B.7 S.Unit......................................................................................................................B-4
B.8 Expand Menu..........................................................................................................B-4
B.9 Reset Menu.............................................................................................................B-4
B.10 End Menu ...............................................................................................................B-4
LIST OF TABLES
TABLE NO. TITLE Page No.
1-1 Specifications –Valor 4000 .................................................................................1-2
1-2 Specifications –Valor 2000 .................................................................................1-2
1-3 Controls Functions Valor 4000.............................................................................1-3
1-4 Battery Charge Status .........................................................................................1-4
1-5 Menu Structure....................................................................................................1-5
1-6 Controls Functions Valor 2000.............................................................................1-6
1-7 Battery Charge Status .........................................................................................1-7
2-1 Load Cell Resistance Readings (in Ohms) ..........................................................2-2
2-2 Color Code for Load Cell Wiring ..........................................................................2-2
2-3 Load Cell Output Readings (in mV with 3.3V Excitation)......................................2-3
2-4 Diagnostic Guide.................................................................................................2-6
3-1 Mounting Bolt Torque Settings.............................................................................3-5
3-2 Overload Stop Gap Settings................................................................................3-6
4-1 Test Mass Values................................................................................................4-1
4-2 Repeatability Worksheet......................................................................................4-4

TABLE OF CONTENTS
Ohaus Corporation www.ohaus.com iii Valor™2000/4000 Series Service Manual
4-3 Linearity Test Masses..........................................................................................4-5
5-1 Housing & Internal Parts Valor 4000PW..............................................................5-3
5-2 Housing & Internal Parts Valor 4000XW ..............................................................5-5
5-3 Housing & Internal Parts Valor 2000PW ..............................................................5-7
5-4 Housing & Internal Parts Valor 2000XW ..............................................................5-9
LIST OF ILLUSTRATIONS
FIGURE NO. TITLE
1-1. Front Display with controls Valor 4000.................................................................1-3
1-2. Back Display Valor 4000......................................................................................1-4
1-3. Front Display with controls Valor 2000.................................................................1-6
1-4. Back Display Valor 2000......................................................................................1-7
1-5. Menu Structor Valor 2000....................................................................................1-8
1-6 Sealing ................................................................................................................1-9
2-1 Main Printed Curcuit Board..................................................................................2-3
3-1 Screws securing Top Housing .............................................................................3-2
3-2 Top and Bottom Bottom.......................................................................................3-2
3-3 Main Printed Circuit Board...................................................................................3-3
3-4 Bolts holding Frame to the Load Cell...................................................................3-4
3-5 Overload stops ....................................................................................................3-5
3-6 Overload Gap positions .......................................................................................3-6
4-1 Scale drawing of Load Cell and Weighing Pan ....................................................4-6
5-1 Housing & Internal Parts......................................................................................5-2

CHAPTER 1 GETTING STARTED
Valor™2000/4000 Series Service Manual 1-1 Ohaus Corporation www.ohaus.com
1.1 INTRODUCTION
This service manual contains the information needed to perform routine maintenance and
service on the Ohaus Valor 2000/4000 Series scales. Familiarity with the scale’s Instruction
Manual is assumed. The contents of this manual are contained in five chapters:
Chapter 1 Getting Started –Contains information on service facilities, tools and test
equipment, specifications, and the mechanical and electronic functions of the scale.
Chapter 2 Troubleshooting –Contains a diagnostic guide and error code table.
Chapter 3 Maintenance Procedures –Contains preventive maintenance procedures and
disassembly, repair and replacement procedures.
Chapter 4 Testing –Contains a list of required test masses, an operational test, segment
display test, performance tests and adjustments.
Chapter 5 Drawings and Parts Lists –Contains exploded views of Valor 2000/4000
scales identifying all serviceable components.
Appendix A Standard Calibration –Explains procedures for Standard Calibration,
performed prior to using a scale, and after service.
Appendix B Service Calibration –Describes the Service Menu and sub-menus, which
allow authorized service personnel to perform factory Linearity and Span calibrations (no
pre-set limits), take Ramp readings, and to set the service menu units.
1.2 SERVICE FACILITIES
To service a scale, the service area should meet the following requirements:
Should be temperature controlled and meet scale specifications for temperature
environmental requirements.
Must be free of vibrations such as fork lift trucks close by, large motors, air currents
or drafts from air conditioning/heating ducts, open windows, people walking by, fans,
etc.
Area must be clean and free of excessive dust.
Work surface must be stable and level.
Scale must not be exposed to direct sunlight or radiating heat sources.
Use an approved Electro-Static Device.
1.3 TOOLS AND TEST EQUIPMENT REQUIRED
The service shop should contain the following equipment:
1. Standard hand tools.
2. Digital Voltmeter (DVM).
3. Standard Electronics tool kit.
4. Grounding mat and clip.
5. Strain Gauge Simulator.

CHAPTER 1 GETTING STARTED
Ohaus Corporation www.ohaus.com 1-2 Valor™2000/4000 Series Service Manual
1.4 SPECIFICATIONS - Valor 4000
Complete specifications for the Ohaus Valor 4000 scales are listed in Table 1-1. When a
scale has been serviced, it must meet the specifications listed in the table. Before servicing
the scale, determine what specifications are not met.
TABLE 1-1. SPECIFICATIONS –Valor 4000
Model
V41PWE1501T
V41XWE1501T
V41PWE3T
V41XWE3T
V41PWE6T
V41XWE6T
V41PWE15T
V41XWE15T
Capacity
1.5 kg
3 kg
6 kg
15 kg
e(g)
0.5
1
2
5
d(g)
0.2
0.5
1
2
Resolution (based on gram)
7500
6000
6000
7500
Max Capacity (lb)
3
6
15
30
Readability (LFT OFF) (lb)
0.0005
0.001
0.002
0.005
Readability (LFT ON) (lb)
0.001
0.002
0.005
0.01
Resolution (LFT ON)
3000
3000
3000
3000
Linearity error (d or e)
1
1
1
1
Repeatability (d or e)
1
1
1
1
Hysteresis (d or e)
1
1
1
1
Off Center Load (d)
1
1
1
1
Creep (d or e)
0.5e (0-15min); 0.2e (15-10min)
Stabilization Time (seconds)
0.5
0.5
0.5
0.5
Operating Temperature
-10C to 40C
-10C to 40C
-10C to 40C
-10C to 40C
Storage Temperature
-20C to 55C
-20C to 55C
-20C to 55C
-20C to 55C
Pan Size
190 x 242 mm
190 x 242 mm
190 x 242 mm
190 x 242 mm
1.5 SPECIFICATIONS - Valor 2000
Complete specifications for the Ohaus Valor 2000 scales are listed in Table 1-2. When a
scale has been serviced, it must meet the specifications listed in the table. Before servicing
the scale, determine what specifications are not met.
TABLE 1-2. SPECIFICATIONS –Valor 2000
Model
V22PWE1501T
V22XWE1501T
V22PWE3T
V22XWE3T
V22PWE6T
V22XWE6T
V22PWE15T
V22XWE15T
Capacity
1.5 kg
3 kg
6 kg
15 kg
e(g)
0.5
1
2
5
d(g)
0.2
0.5
1
2
Resolution (based on gram)
7500
6000
6000
7500
Linearity error (d or e)
1
1
1
1
Repeatability (d or e)
1
1
1
1
Hysteresis (d or e)
1
1
1
1
Off Center Load (d)
1
1
1
1
Creep (d or e)
0.5e (0-15min); 0.2e (15-10min)
Stabilization Time (seconds)
0.5
0.5
0.5
0.5
Operating Temperature
-10C to 40C
-10C to 40C
-10C to 40C
-10C to 40C
Storage Temperature
-20C to 55C
-20C to 55C
-20C to 55C
-20C to 55C
Pan Size
190 x 242 mm
190 x 242 mm
190 x 242 mm
190 x 242 mm

CHAPTER 1 GETTING STARTED
Valor™2000/4000 Series Service Manual 1-3 Ohaus Corporation www.ohaus.com
1.6 SCALE OPERATION –VALOR 4000
This section contains information on the basic operation of the Valor 4000 scale.
1.6.1 OVERVIEW OF THE CONTROLS
Figure 1-1. Valor 4000 Front Display with controls.
TABLE 1-3. Control functions Valor 4000
Button
Functions
Short Press1(when on): Sets display to zero
Long Press2(when off): Turns scale on
(when on): Turns the scale off3
Short Press (in Menu): Selects / accepts displayed setting
Short Press: Accumulates the weight or displays the
accumulated information at 0 load.
Long Press: Toggles through active Units
Short Press (in Menu): Toggles through available settings
Short Press: Initiates an application mode specific response
Long Press: Selects active Mode
Short Press (in Menu): returns to previous settings
Short Press: Enter / clear a Tare value
Long Press: Enters User Menu
Short Press (in Menu): Quickly exit User Menu
IR Sensor4can be programmed to act as “touchless” button. See
the User Menu section 4.3 for the available settings.
Notes:
1 Short Press: Press less than 2.5 seconds.
2 Long Press: Press and hold for more than 2.5 seconds.
3 Press and hold the On/Zero Off button until OFF is displayed, then release the button.
4 The IR sensor can be activated by a hand or other object that is placed at a
specified height above the sensor location. The sensor activation distance will vary
based on the reflective nature of the object. If unwanted activations occur due to
unique situations the sensor can be turned off.

CHAPTER 1 GETTING STARTED
Ohaus Corporation www.ohaus.com 1-4 Valor™2000/4000 Series Service Manual
LED Indicators
Figure 1-2. Valor 4000 Back Display.
1.6.2 Power ON/OFF
To turn the scale on, press and hold the On/Zero Off button for 2.5 second. The scale
performs a display test, momentarily displays the software version, and then enters the
active weighing mode.
To turn the scale off, press and hold the On/Zero Off button until OFF is displayed.
The scale can be used on AC power immediately. Allow the battery to charge for 12
hours before using the scale on battery power. The Scale will automatically switch to
battery operation if there is a power failure or the power cord is removed. With AC
power, the scale is constantly charging, so the battery charge indicator will remain lit.
The scale can be operated during charging, and the battery is protected against
overcharging.
For maximum operating time, the battery should be charged at room temperature.
During battery operation, the battery symbol indicates the battery charge level
remaining. When charging, the symbol will blink slowly and when fully charged the
symbol will stop blinking.
TABLE 1-4
Symbol
Charge Level
Battery in use:
Symbol displayed
Notes:
When battery symbol blinks fast, approximately 30 minutes working time is left.
When [lo.bat] is displayed, the scale will shut off.
Charging the scale must be performed in a dry environment.
CAUTION: Battery is to be replaced only by an authorized Ohaus
service dealer. Risk of explosion can occur if the rechargeable
battery is replaced with the wrong type or if it is not properly
connected. Dispose of the lead acid battery according to local laws
and regulations.
IR Sensor (back)

CHAPTER 1 GETTING STARTED
Valor™2000/4000 Series Service Manual 1-5 Ohaus Corporation www.ohaus.com
1.6.3 Menu Setup
Programmable features of the Valor 4000 scales are contained in menus which are
accessed through the Display Panel’s control switches. See the Instruction Manual for a full
description of the menus and how to access them.
TABLE 1-5. Valor 4000 MENU STRUCTURE
Menu:
C.A.L
S.E.t.U.P
r.E.A.d
M.O.d.E
U.n.i.t
L.O.C.k
E.n.d
Menu
Items:
Span
Lin
GEO
End
Reset
Pwr.Un
A.Tare
Ir.Func
Ir.Adj
Accum
End
Reset
Stable
Filter
AZT
Light
Sleep
A.Off
End
Reset
Percnt
Check
End
kg
g
oz
lb
lb:oz
End
Reset
L.Cal
L.Setup
L.Read
L.Mode
L.Unit
End
1.6.4 Menu Navigation
Press and hold Menu until [mMeNU] (Menu) is displayed. When released the first sub-menu
[C.a.l] (Cal) will be shown.
Press Yes to enter the displayed sub-menu or press No to advance to the next.
Selecting a sub-menu will display the first menu item. Press Yes to view the menu item
setting or press No to move to the next menu item. When viewing the setting, press Yes to
accept the setting, or press No to change the setting. When [End] is displayed, press Yes to
return to the sub-menu selections or No to return to the first item in the current menu. Bold
indicates factory default setting.

CHAPTER 1 GETTING STARTED
Ohaus Corporation www.ohaus.com 1-6 Valor™2000/4000 Series Service Manual
1.7 SCALE OPERATION –VALOR 2000
This section contains information on the basic operation of the Valor 2000 scale.
1.7.1 OVERVIEW OF THE CONTROLS
Figure 1-3. Valor 2000 Front Display with controls.
TABLE 1-6. Control functions Valor 2000
Button
Functions
Short Press1(when on): Sets display to zero
Long Press2(when off): Turns scale on
(when on): Turns the scale off
Short Press (in Menu): Selects / accepts displayed setting
Short Press: Enter / clear a Tare value
Long Press: Initiates Calibration procedure
Short Press (in Menu): Toggles through available settings
Extended Press3: Enters user menu
Notes:
1Short Press: Press less than 2.5 seconds.
2Long Press: Press and hold for more than 2.5 seconds.
3Extended Press: Press and hold for more than 5 seconds.
On/Zero
Off
Tare
Cal

CHAPTER 1 GETTING STARTED
Valor™2000/4000 Series Service Manual 1-7 Ohaus Corporation www.ohaus.com
Figure 1-4. Valor 2000 Back Display.
1.7.2 Power ON/OFF
To turn the scale on, press and hold the On/Zero Off button for 2.5 seconds. The scale
performs a display test, momentarily displays the software version, and then enters the
active weighing mode.
To turn the scale off, press and hold the On/Zero Off button until OFF is displayed.
The scale can be used on AC power immediately. Allow the battery to charge for 12
hours before using the scale on battery power. The Scale will automatically switch to
battery operation if there is a power failure or the power cord is removed. With AC
power, the scale is constantly charging, so the battery charge indicator will remain lit.
The scale can be operated during charging, and the battery is protected against
overcharging.
For maximum operating time, the battery should be charged at room temperature.
During battery operation, the battery symbol indicates the battery charge level
remaining. When charging, the symbol will blink slowly and when fully charged the
symbol will stop blinking.
TABLE 1-7
Symbol
Charge Level
Battery in use:
Symbol displayed
Notes:
When battery symbol blinks fast, approximately 30 minutes working time is left.
When [lo.bat] is displayed, the scale will shut off.
Charging the scale must be performed in a dry environment.
CAUTION: Battery is to be replaced only by an authorized Ohaus
service dealer. Risk of explosion can occur if the rechargeable
battery is replaced with the wrong type or if it is not properly
connected. Dispose of the lead acid battery according to local laws
and regulations.

CHAPTER 1 GETTING STARTED
Ohaus Corporation www.ohaus.com 1-8 Valor™2000/4000 Series Service Manual
1.7.3 Menu Setup
Programmable features of the Valor 2000 scales are contained in menus which are
accessed through the Display Panel’s control switches. See the Instruction Manual for a full
description of the menus and how to access them.
Cal
Figure 1-5. Menu structure
1.7.4 Menu Navigation
To enter the calibration menu, press and hold the Cal button for 5 seconds, [SpaN] will then
be displayed. Press Zero key to perform span calibration or press Cal key to proceed to
GEO settings. Press Zero key to enter GEO settings and then press Cal key to increase the
value. Press Zero key to confirm, [end] will be displayed. Press Zero key to exit the menu
and return to weighing mode.
Span
GEO
End

CHAPTER 1 GETTING STARTED
Valor™2000/4000 Series Service Manual 1-9 Ohaus Corporation www.ohaus.com
1.8 LEGAL FOR TRADE
Note: This section applies to Valor 4000 only.
When the scale is used in trade or a legally controlled application it must be set up, verified
and sealed in accordance with local weights and measures regulations. It is the
responsibility of the purchaser to ensure that all pertinent legal requirements are met.
To Lock or Unlock the scale’s Legal-For-Trade (LFT) settings, follow this procedure:
Caution: When accessing the bottom of the scale, avoid placing the scale upside down on
the pan or sub-platform. Place the scale on its side.
1. Turn the scale OFF.
2. Remove the Security Cover under the scale to access the two pins located in a slot.
Short these pins (a slotted screwdriver may be used), while powering the scale ON.
The scale will perform the start-up procedure, and then the display will show the
current status [lft OFF] (LFT OFF, unlocked) or [lft ON] (LFT ON, locked); press the
‘No’ key to change this setting, or press the ‘Yes’ key to confirm it.
Note: When Legal For Trade is set to On, the menu setting are affected as
follows:
Calibration (C.A.L) menu is not accessible
Unit menu is locked at the current setting
Filter Menu is locked at current setting
IR function menu is locked at current setting
Stable Range setting is locked at 1d
Auto-Zero Tracking setting is locked at 0.5d
3. Replace the Security Cover.
1.8.1 Physical Seals
For jurisdictions that use the physical sealing method, the local weights and measures
official or authorized service agent must apply a security seal to prevent tampering with the
settings. Refer to the illustrations below for sealing methods.
Figure 1-6. Sealing
Unlocked
Locked

CHAPTER 2 DIAGNOSTIC GUIDE
Valor™2000/4000 Series Service Manual 2-1 Ohaus Corporation www.ohaus.com
2.1 TROUBLESHOOTING
This section of the manual contains troubleshooting information. Information is contained to
isolate specific problems using Table 2-4, Diagnostic Guide. Follow all directions step by step.
Make certain that the work area is clean. Handle balance components with care. Use
appropriate Electro-Static Device.
2.2 DIAGNOSTIC GUIDE
Table 2-4 is a Diagnostic Guide designed to help locate the problem area quickly and easily.
The probable causes are listed with the most common cause first. If the first remedy does not fix
the problem, proceed to the next remedy. Before attempting to repair the balance, read all
chapters of this manual to be familiar with the balance components and operation.
2.2.1 Diagnosis
1 Isolate and identify the symptom.
2 Refer to Table 2-4, Diagnostic Guide and locate the symptom.
3 Follow the suggested remedies in the order they appear.
4 Perform the indicated checks, or see the appropriate section of the manual.
5 Repair or replace the defective section of the balance.
NOTE:
If more than one symptom is observed, approach one area at a time, and remember that
the symptoms may be interrelated.
If a problem arises that is not covered in this manual, contact Ohaus Corporation for further
information.

CHAPTER 2 DIAGNOSTIC GUIDE
Ohaus Corporation www.ohaus.com 2-2 Valor™2000/4000 Series Service Manual
2.2.2 Checking Load Cells for Trouble
1. Perform a Resistance Test, to determine if the Load Cell is severely damaged or a
short circuit to the frame has occurred.
Note: The Load Cell must be completely disconnected from the Printed Circuit Board
and at no load when the resistance readings are taken.
Using an ohm meter, measure and record resistance between each pair of wires
from the Load Cell, as specified in Table 2-1. Compare the measured readings with
the specified values in Table 2-1.
If the resistance readings are in the range specified, skip to the next section. If they
are outside the expected range, open circuit or short-circuit across any two wires, the
Load Cell is defective: replace it. (See Chapter 3.)
TABLE 2-1. LOAD CELL RESISTANCE READINGS (in Ohms)
Model
Ex+ to Ex–
S+ to S–
Ex+ to S–
Ex+ to S+
Ex–to S+
Ex–to S–
All models
404 ±10
350 ±4
289 ±10
289 ±10
289 ±10
289 ±10
2. Perform an Output Voltage Test:Measure the no load, 50% load and full load
output. The reading should meet the Load Cell specifications. The Load Cell output
should be very close to linear over its capacity range.
NOTE: The following steps involve power applied to the scale. Load Cell solder
contacts can be used as measuring points. See Figure 2-1.
The EXE+ and EXE–wires should be connected to the PCB, and the SIG+ and SIG–
wires must be disconnected. Record the colors for each wire connection before
disconnecting. (See Table 2-2 for typical color code for Valor 7000.)
TABLE 2-2. COLOR CODE FOR LOAD CELL WIRING*
EXE–
EXE+
SIG+
SIG–
AMI
BLACK
GREEN
WHITE
RED
ZEMIC
BLACK
RED
GREEN
WHITE
*Color codes may vary.
–Insert the Platform Support into the Load Cell Frame, place the Platform on top,
and turn on power to the scale.
–Using a voltmeter, measure and record the excitation voltage supplied to the
PCB: with no load on the Platform, measure the voltage across points 4 and 1 of
Load Cell connection on the PCB (+EXE and –EXE). This voltage must be
approximately 4.6~4.7 Volts dc with the Load cell connected. If the voltage is
lower, disconnect the Load Cell cable from the PCB and measure again. If the
voltage is not 4.6~4.7 Volts dc, the Load Cell is defective and must be replaced.
If the voltage remains low, the PCB is defective and must be replaced.

CHAPTER 2 DIAGNOSTIC GUIDE
Valor™2000/4000 Series Service Manual 2-3 Ohaus Corporation www.ohaus.com
CAUTION:
IN THE NEXT STEP, DO NOT OVERLOAD THE SCALE BEYOND FULL
CAPACITY RATING.
–Measure the voltages on +SIG and –SIG wires, disconnected from PCB.
Note: Measurements must be made with these wires disconnected from the
PCB. These measurements represent the output of the Load Cell. Record
measurements at Zero Load, 50% and full scale capacities. See Table 2-3 for
typical readings.
Figure 2-1. Top view of main PCB.
NOTE: Table 2-3 indicates typical readings. Actual values can vary, but should
remain linear throughout the range. If readings are out of tolerance, replace the
Load cell. (See Section 3.6.)
TABLE 2-3. LOAD CELL OUTPUT READINGS (in mV/V with 4.65 V Excitation)
Model/Capacity
Zero Load
50% Load
100% Load
V41xWE1501T / 1.5kg
V22xWE1501T / 1.5kg
0.739
1.489
2.239
V41xWE3T / 3kg
V22xWE3T / 3kg
0.4434
1.3434
2.2434
V41xWE6T / 6kg
V22xWE6T / 6kg
0.2217
1.1217
2.0217
V41xWE15T / 15kg
V22xWE15T / 15kg
0.11085
1.23585
2.36085

CHAPTER 2 DIAGNOSTIC GUIDE
Ohaus Corporation www.ohaus.com 2-4 Valor™2000/4000 Series Service Manual
2.2.3 Testing the Printed Circuit Board (PCB)
The PCB can be tested by measuring voltages and by using a simulator. The simulator replaces
the Load Cell during testing and is a useful tool for diagnosing problems.
PCB Voltage Measurements
Note: Prior to the voltage measurements, the battery should be fully charged and tested.
1. Disconnect power from the scale, and remove the Top housing. (See Section 3.3.1.)
CAUTION: Disconnect the power from the scale before opening the housing.
2. Connect the AC Adapter to the scale and turn the scale on.
3. Using a DVM, measure the excitation voltage (EXE+ and EXE–in Figure 2-1.)
The reading should be 4.6~4.7 volts dc. This is the excitation voltage for the Load
Cell
and is regulated. If the voltage is lower, replace the PCB. (See Section 3.4.)
Then perform Operational Tests. (See Chapter 4.)
4. Measure incoming power from the transformer connector shown in Figure 2-1. The
voltage should read 0 volts with power off and above 12 Volts dc with power on.
5. Perform simulator testing.
Simulator Testing
To perform these tests, the use of a Simulator is required. The function of a Simulator is to
simulate the output of a full bridge Load Cell, allowing the scale to be separated from the Load
Cell for the purposes of troubleshooting and calibration. The Load Cell used in the scale is rated
at 2mV/V output with a 4.6~4.7 Volt excitation voltage applied.

CHAPTER 2 DIAGNOSTIC GUIDE
Valor™2000/4000 Series Service Manual 2-5 Ohaus Corporation www.ohaus.com
General Load Test
This test checks the Main PC Board circuitry by simulating accurate Load Cell voltages at zero
load, 50% and 100% load capacities.
Disconnect power from the scale, and remove the Top housing. (See Section 3.3.1.) Leave the
Mechanical Switch connected to the scale. Disconnect the battery.
1. Disconnect the Load Cell cable from the main PC Board.
2. With the Simulator set to zero, solder its cable leads to their counterparts on the
PCB, using the Load Cell Cable solder points on the PCB. (See Figure 2-1.).
3. Connect a known good AC Adapter to the scale and connect to a power source.
4. Turn on the scale. An under load error may appear. This is normal.
5. Set the scale to indicate weight in kilograms (kg) and set the calibration value to
maximum span value.
6. Adjust the Simulator to simulate 0% load, 50% load and 100% load for the capacity
that the scale is rated for. (See Table 2.3 for values to use.) If the resulting readings
are unstable, the Main PC Board is defective.
7. Use the Simulator to calibrate the scale in the next procedure to verify if the Main PC
Board is good or bad.
Calibration Test
This test calibrates the scale using the simulator and can verify that the Main PC Board is
functioning properly or improperly.
1. With the scale on, enter the scale menu and perform a span calibration.
(See Appendix A.)
2. Follow the scale prompts. When the scale indicates a given weight to be placed
on the scale, set the simulator to an equivalent value based on Table 2-3.
3. Upon completion of calibration, the PCB can be further checked using the Simulator
to simulate various weight values. If simulator settings and weight readings on the
scale agree, the PCB is functional. If the scale readings vary, or do not agree with
readings in Table 2-3, the Main PC Board is defective and should be replaced.
(See Chapter 3.)