LG LAC-M3600R Service Manual page 7

2. LCD light abnornal.
Any Key power on.
(without DISC)
Do display LCD then light?
NO
Check voltage in the power
supply
YES
Is u-com IC906 LCD reset
circuit normal?Pin74
YES
Is u-com IC906 X1,X2 terminal
Pin11,12,14,15 input?
OSC :19.2MHz
OSC :32.768kHz
YES
Is u-com IC906 keyin
Pin19,20 5volt input?
YES
Is u-com IC906 Pin 74,75,76
output waveform normal?
YES
Is IC901 Com1, Com2, Com3
output waveform normal?
YES
Display LCD connector
defective.
- 2-2 -
NO
Power supply circuitry defective.
Q371,Q372,IC403
NO
• Reset circuit defective.
IC901 Surrounding circuit
defective.
NO
X101,X102,C101,
C102,C103,C104.
NO
Q921,ZD910
PCB pattern defective.
NO
IC906,Pin74,75,76
front PCB pattern defective.
NO
IC901,Surrounding circuit
PCB pattern defective.