LG 42LA86 Series Service Manual page 101

Standard Repair Process
Error
LCD TV
symptom
1. Remote control(R/C) operating error
Check R/C itself Normal
operating?
Operation
N
Check R/C Operating Check & Replace
When turn off light Baterry of R/C
in room
If R/C operate,
Explain the customer
cause is interference
from light in room.
D. General Function Problem
Remote control & Local switch checking
☞A27
Check & Repair
Y
Cable connection
Connector solder
Normal
Close
operating?
N
Replace R/C
☞A27
N
Normal Check B+ 3.5V
operating?
On Main B/D
Y
☞A4
Close
Check 3.5v on Power B/D
(Power B/D don't have problem)
Established
2012. 12 .06
date
Revised date
☞A27
Y
Normal Check IR
Voltage?
Output signal
N
Replace Power B/D or
Replace Main B/D
Replace
Main B/D
Y
Normal
Signal?
N
Repair/Replace
IR B/D