LG OLED55B7P Service Manual page 58

Standard Repair Process Detail Technical Manual
Error
Established
A. Video error_Color error
symptom
date
Revised
Adjustment Test pattern
Content A15
date
1
2
3
Press the P-ONLY  HDMI HOT  CH + or -
You can view 11 types of patterns using the CH+ or - key
Checking item : 1. Defective pixel 2. Residual image 3. MODULE error (ADD-BAR,SCAN BAR..)
4.Video error (Classification of MODULE or Main-B/D!)
A15