LG StudioWorks 570LE Service Manual page 20

4. NO RASTER (OSD IS DISPLAYED) – TDA8752BH
NO RASTER
(OSD IS DISPLAYED)
YES
U1
POWER PIN
5V?
YES
U1 PIN3
2.5V?
YES
CHECK
R,G,B INPUT?
U1 PIN 12, 20, 28
YES
CHECK
IIC PULSE ?
U1 PIN32, 33
YES
CHECK
CKREF(H-SYNC) INPUT?
U1 PIN94
YES
CHECK
H-SYNC INPUT?
U1 PIN90?
YES
NO
NO
NO
NO
NO
NO
- 19 -
CHECK U17, +5V
CHECK U101
1. CHECK PC
2. CHECK SIGNAL CABLE
& D-SUB CONNECTOR
LINE
CHECK IIC LINE
CHECK H-SYNC LINE
(D-SUB U8 MICOM
U1 PIN95)
CHECK CKREF INPUT