Display Backlight Troubleshooting Flow Chart - Thermo Scientific PARTISOL 2000 Service Manual

DISPLAY BACKLIGHT TROUBLESHOOTING FLOW CHART

Backlight not on
Power system
off then on.
Hit several keys on
the keypad.
Go to diagnostics
Is backlight on? No screen and turn on
backlight.
Yes
Resume normal
operation.
Key on keypad pressed
before may be bad.
Yes
Check status of LED
Is backlight on? No "BLITE" on interface
board.
Is LED on?
No
Perform a system
reset and recheck
the LED.
LED on?
No
Replace interface/CPU
board assembly
R&P P/N 50-005496
& 10-002407
Note:
1. Pins for continuity check of cable P16B to display:
P16B Display
Pin 1 A
Pin 2 K
Replace display
R&P P/N 10-002254
Check continuity of cable
P16B (interface board)
Yes Continuity OK?
and display connection
(see note 1).
Replace cable
R&P P/N 51-004665
Yes Recheck backlight.
Yes
No