LG 55UJ634 Series Service Manual page 56

Standard Repair Process Detail Technical Manual
symptom
Content
<ALL MODELS>
Error
A. Video error_Video error, video lag/stop
TUNER input signal strength checking method
Established
date
Revised
date
Advanced Channels
Manual Tuning
A3

Channel Tuning
When the signal is strong,
use the attenuator (-10dB, -
15dB, -20dB etc.)
A3