CHAPTER 2 TROUBLESHOOTING
Adven
turer ™ Balances Service Manual 19 Ohaus Corporation www.ohaus.com
Table 2-1 Diagnostic Guide
SYMPTOM
PROBABLE CAUSE
REMEDY
Balance will not turn
on with AC adapter
supplied
Main power source is off
Adapter defective
Input connector at rear of
Balance may be defective
A defective keypad
membrane
Main PC Board defective.
Check the main power source outlet for
proper voltage.
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. 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.
Replace the keypad membrane.
Replace the Main PC Board.
Balance does not
respond to front panel
controls.
Main PC Board is defective
A defective keypad
membrane
Replace the Main PCB.
Replace the keypad membrane.
Poor accuracy.
Unstable environment.
Balance out of calibration.
Balance was not re-zeroed
before weighing.
Move balance to suitable location;
ensure that balance is level.
Calibrate the balance.
Press
>O/T<
with no weight on the pan,
then weigh item.
Balance can be turned
on but will not calibrate
manually.
Incorrect weights.
Balance not level.
Balance is unstable.
Load cell assembly
defective.
PCB is defective.
Verify that proper weights are used.
Level the balance.
Perform Automatic Internal Calibration.
Enter Service mode (Appendix B) and
perform a Span Calibration. If this fails,
check the InCal Weight Assembly and
the Load Cell Assembly. Ensure that
all parts are clean and properly aligned.
Repair the Load Cell.
Replace the PCB.
Balance will not
calibrate using internal
calibration, but
calibration motor is
working.
Unstable environment.
InCal Mechanism may be
misaligned, or not moving
smoothly.
Move the balance to a location without
draft or vibration.
Level the balance using leveling feet on
rear of chassis, together with leveling
bubble.
Use software tool to test mechanism.
(See Section B.8, Appendix B.)
To correct problem, see Section 3.6.5.
Calibration Motor is
not working.
Calibration Motor may be
defective
Remove the Calibration Motor;
check the Calibration Motor with
software tool (See Section B.8,
Appendix B.), replace if defective.
If motor is OK, continue with testing