Checking The Interface Circuit Of Sync Signal; Checking The Control Circuit Of Horizontal Sync Pulse For Vga; Checking The Control Circuit Of Vertical Sync Pulse Vga - HP R15AAC Service Manual

9.

Checking the interface circuit of sync signal

9.1 Checking the control circuit of horizontal sync pluse for VGA
Check the horizontal sync signal on P302 pin13 TTL
Check the horizontal sync signal on I307 pin189 TTL
Failure Point
Process "Checking the resolution change IC
movement" section.
9.2 Checking the control circuit of vertical sync pluse for VGA
Check the horizontal sync signal on P302 pin14 TTL
Check the horizontal sync signal on I307 pin90 TTL
Failure Point
Process "Checking the resolution change IC
movement" section.
Page 22
level.
NG
OK
level.
NG
OK
level.
NG
OK
level.
NG
OK
R15AAC/AAU (vs15)
Failure Point
VGA Video cable is failure.
Failure Point
1) Printed wire broke between P302 pin13 and
I307 pin189.
2) R323 is open.
3) R326, C335 are short.
Failure Point
VGA Video cable is failure.
Failure Point
1) Printed wire broke between P302 pin13 and
I307 pin90.
2) FB315, R324 are open.
3) R325, C334 are short.