Only For Training And Service Purposes - LG KC780 Service Manual

START
Connect power
supply to the DUT
Vbat = over 3.35V
Yes
Check
"PWRON" signal of
TP1 2.0V
Check Combination
CN101 of Key PCB
when push the
power key
Check
"PWRON" signal of
TP1 0V
Yes
Check the all LDO's
output
Is it correct?
Is the 26MHz
clock from TP2
X101 of U104 ?
Replace main PCB
Copyright © 2008 LG Electronics. Inc. All right reserved.

Only for training and service purposes

No
Yes
No
(Key PCB Connector)
Yes
No
No
No
Check the
BACKUP Battery
Check Combination
CN101
or
Replace CN101
Check solder
Q401
Check solder whole LDO
parts or replace it
Check solder
Replace X-TAL
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5. TROUBLE SHOOTING
LGE Internal Use Only