Samsung DV7720KV Service Manual page 28

Troubleshooting
6-4 No Video Signal
check for video
signal at PIN 70
check for DIGITAL
signal at PIN 48 THRUY
check for V-sync signal
at PIN 39 of VIC 1
check for IRQ signal
at PIN 90 of VIC 2
check for HREF,PBHD
PIN 41,43 of VIC 2
See "Blue - background not shown"
Samsung Electronics
of VIC 1
Yes
PIN 55 of VIC 2
Yes
Yes
Yes
signal at
Yes
No
check for video
signal at emitter
of VQ1
Replace VIC3
No
No
No
No
No
Replace VQ1
Replace VIC 1
Replace VIC 2
See "LD DOES NOT PLAY"
6-4