LG GD310 Service Manual page 69

5. TROUBLE SHOOTING
START
Connect power
supply to the DUT
Vbat = over 3.35V
"PWRON" signal
Check 3 pin of Q200
"_RESET" signal
Check 5 pin of U202
Check the all LDO's
output
Is it correct?
Is the 26MHz
clock From U400
signal correct?
Replace main PCB
LGE Internal Use Only
Yes
No
Yes
No
Yes
No
Yes
No
Yes
X400
U400
Check the
RPWRON,
replace Q200
Check solder
U202 or replace it
Check solder
U201 or replace it
Check solder X400, U400
or replace it
Check 3 pin of X400
Or Check 14 pin of U400
- 70 - Copyright © 2009 LG Electronics. Inc. All right reserved.
TP1
Q200
TP2
14pin of U400
3pin of X400
Only for training and service purposes
U202
U201