LG Prada KE850 Service Manual page 77

5. Trouble shooting
START
Connect power
supply to the DUT
Vbat = over 3.35V
Yes
"PWRON" signal
= VBAT?
Yes
"_RESET" signal
goes to high?
Yes
Check the all
LDO's output
Is it correct?
Yes
Is the 26MHz
clock From U402
signal correct?
Yes
Replace main PCB
- 78 -
No
Check the
RPWRON,
replace U204
No
Check solder
U206 or replace it
No
Check solder
U201 or replace it
No
Check solder
X401, U403
or replace it