Sony XR-55A75L Service Manual page 73

TROUBLESHOOTING
2.3 LED Blinking: 4x (LD_ ERR) – XR-83A80*
Check "LD_ERR_DET" Voltage
BM5S21 : CL5206
4x blinking
(LD_ERR)
High (3.3V)
Low (0V)
B* Board
No
LCD model ?
Yes
NG
Replace LD board
Symptom
Improvement
LD Board
Panel
73
SYS SET