LG 55UB820T Service Manual page 70

Standard Repair Process Detail Technical Manual
Error
Established
error_No
A. Video video/Normal audio 2013.01.31
symptom
date
LCD TV
Revised
Content Check LCD back light with naked eye A1
date
<XXUB83/820X-XX>
After turning on the power and disassembling the case, check with the naked eye,
whether you can see light from locations.
* Tuner is different from region
A1