Chadwick-Helmuth Vibrex 2000 Plus User Manual page 162

Chapter 6 - Maintenance
Possible Cause
Internal short circuit
Problem: Display Too Light
Contrast incorrectly
adjusted
The -12V power
short-circuited
Unit too cold
Problem: Unit Not Responding to Certain Keys
Keyboard connector
loose, offset, or
damaged
Keyboard failure
Problem: Unit Repeatedly Turning Off Unexpectedly
Battery end plate
loose
Battery voltage low
Terminals in battery
end plate PCB
corroded and/or dirty
150 Chadwick-Helmuth Company, Inc.
Corrective Action (Continued)
Remove the connector end plate and carefully
inspect internal wires for damage (see
Section 6.3.7.2 "Disassembly" on page 143).
Adjust the contrast by using the two keys to the
right of the screen.
Remove any damaged cables and try again.
Inspect connectors for visible damage.
If the unit has been exposed to low
temperatures (less than 0° F), the display may
not be able to be adjusted dark enough to read.
Move the unit to a warmer place.
Adjust the contrast by using the two keys to the
right of the screen.
Return the unit to the factory for repair.
Check the battery end plate for excessive
looseness; some play is normal. Adjust the
spring(s) on the battery contact PCB assembly,
or replace the battery end plate.
Replace or recharge the batteries.
If the terminals on the battery end plate PCB
are discolored or corroded, clean them with a
pencil eraser.