Panasonic CF-73ECLTXKM - Toughbook 73 - Pentium M 1.4 GHz Service Manual page 20

9.3 LCD DIAGNOSIS
Make sure that connecting cables, connectors and AC adapter are not loose or disconnected prior to testing.
No. Symptom
1 No picture appears on the
screen.
2 Display is too dark or too
bright.
3 Part of the screen does
not display properly.
Display quality poor.
(Fuzzy or slanted, etc.)
4 Backlight does not turn
on.
Troubleshooting
procedures
No.
Does the LCD display
1-1
properly after brightness level
is adjusted?
Replace the LCD.
1-2 Does operation return to
normal?
Replace the Main PCB.
1-3 Does operation return to
normal?
Does the LCD display
2-1 properly after brightness level
is adjusted?
Replace the LCD.
2-2 Does operation return to
normal?
Replace the Main PCB.
2-3 Does operation return to
normal?
Replace the LCD.
3-1 Does operation return to
normal?
Replace the Main PCB.
3-2 Does operation return to
normal?
Replace the Inverter PCB.
4-1 Does operation return to
normal?
Replace the Inverter cable.
4-2 Does operation return to
normal?
Replace the Backlight.
4-3 Does operation return to
normal?
17
Source of
problem
Result
Brightness
YES
adjustment
NO Go to No.1-2
YES LCD
NO Go to No.1-3
YES Main PCB
NO LCD cable
Brightness
YES
adjustment
NO Go to No.2-2
YES LCD
NO Go to No.2-3
YES Main PCB
NO LCD cable
YES LCD
NO Go to No.3-2
YES Main PCB
NO LCD cable
YES Inverter PCB
NO Go to No. 4-2
YES Inverter cable
NO Go to No. 4-3
YES Backlight
NO Main PCB
Component
IC800
CN801
IC14
IC800
CN801
IC14