LG GX500 - Page 76

- 77 -
Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
4. TROUBLE SHOOTING
GX500 Operational Description Revision A
LG Electronics 77/143 LGE Property
14pin of U401
Checking Flow
STAR
T
“PWRON” signal
Check 3 pin of U203
Check the all LDO’s
output
Is it correct?
Replace main PCB
Check the RPWRON,
replace Q201
Check solder
U201 or replace it
Check solder X401
or replace it
Check 3 pin of X401
Or Check 11 pin of U401
Yes
Yes
Yes
Yes
No
No
No
Connect power
supply to the DUT
Vbat = over 3.35V
Q201
TP1
X401
U201
1pin of X401
U401
Is the 26MHz
clock From X401
signal correct?
Figure 4-3. RPWRON
Figure 4-5. X-TAL & Transceiver
GX500 Operational Description Revision A
LG Electronics 77/143 LGE Property
14pin of U401
Checking Flow
STAR
T
“PWRON” signal
Check 3 pin of U203
Check the all LDO’s
output
Is it correct?
Replace main PCB
Check the RPWRON,
replace Q201
Check solder
U201 or replace it
Check solder X401
or replace it
Check 3 pin of X401
Or Check 11 pin of U401
Yes
Yes
Yes
Yes
No
No
No
Connect power
supply to the DUT
Vbat = over 3.35V
Q201
TP1
X401
U201
1pin of X401
U401
Is the 26MHz
clock From X401
signal correct?
Figure 4-3. RPWRON
Figure 4-5. X-TAL & Transceiver