OHAUS Valor 1000W, Service Manual

Page: 16 / 44

CHAPTER 2 DIAGNOSTIC GUIDE
Ohaus Corporation www.ohaus.com 2-4 Valor
™ 1000W Series Service Manual
2.2.3 Diagnostic Guide
TABLE 2-4. DIAGNOSTIC GUIDE
Symptom Possible Cause Remedy
Scale will not turn
on. No power to scale
Battery power exhausted
Adapter defective
Input connector at rear of
balance may be defective
On/Off switch defective or
actuating fingers on top housing
defective.
Main PC Board defective.
Verify connections and voltage.
Connect power and charge battery.
Check the AC adapter voltage
output which should match the
specified voltage on the adapter.
If voltage is low or nonexistent,
replace the AC adapter. If OK,
Proceed.
Open the balance. Leave the cable
connected to the top housing.
Reconnect the AC adapter to the
balance. Check AC voltage at the
input connector terminals. It should
read 12 V AC.
If voltage is not present, replace the
input connector. If OK, proceed.
( Caution: disconnect the AC
adapter and remove power and/or
batteries from the balance for this
procedure, to prevent damage to the
ohmmeter.)
Open the balance. Using an ohm-
meter, measure the resistance
between the pins on the On/ Off
switch. It should be open. If
continuity is not present, replace the
switch.
Replace the Main PC Board.
Poor accuracy Unstable environment
Balance out of calibration
Balance was not re-zeroed
before weighing.
Move scale to suitable location;
insure that balance is level.
Calibrate the balance.
Press Zero with no weight on the
pan, then weigh item.
Unable to calibrate Unstable environment
Incorrect calibration mass
Up and down stops out of
adjustment.
Load Cell defective.
Move scale to suitable location.
Use correct calibration mass.
Remove the cover from the load
cell. Check the Overload Stops.
(See Section 3.7.) If OK, the load
cell is defective.
Replace the Load Cell. (See
Section 3.6.)