LG 75SM9400PTA Service Manual page 74

Standard Repair Process Detail Technical Manual
symptom
Content
LED Indicator error condition (UHD Mid/High model only)
1. LED Indicator blank in each abnormal condition (Repeat each 6sec)
2. Abnormal condition
1) Open LED Protection
2) Short LED Protection
3) DC/DC voltage level check
4) P-Dim1 error
5) Driver on signal error
6) Local dimming data error
7) Driver IC error or MCU error check
8) V-sync error
Abnormal condition
Normal Operation
Driver IC & MCU Communication Check
LED B+ output voltage Check
Open LED Protection
Short LED Protection
Driver on signal error
P-DIM error
Local dimming data error
V-sync signal error
Error
B. Power error _No power
Error check by LED Indicator
Error signal
message
LED blank 0 times
LED blank 1 times
LED blank 2 times
LED blank 3 times
LED blank 4 times
LED blank 5 times
LED blank 6 times
LED blank 7 times
LED blank 8 times
Established
date
Revised
date
LED Indicator
Remark
Normal Operation
DRV_IC to MCU communication Error
LED B+ OVP/UVP check
Open level detect
Short level detect
Driver on signal is low
PWM signal is low
Local data error (Checksum & Data Length)
V-sync signal is low
A10
< LED Driver BD >
Applied
Edge, Slim Direct
Slim Direct
Edge, Slim Direct
Edge, Slim Direct
Edge, Slim Direct
Edge
Edge
Edge, Slim Direct
Edge, Slim Direct
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A10