On May 8, 11:43*am, "Lance Dyer" wrote:
Bad caps

"William Sommerwerck" wrote in message

...



On modern sets, vertical sync is generated from the horizontal
sync. The
chip that handles sync separation is a likely possibility.

It's also possible the bias on the vertical output stage is
drifting.

I second the bad caps suggestion. I put the odds at 98% dried out
cap(s). The 'warm up' description is exactly how 'lytics behave. they
always measure better after unsoldering. I just changed 72 caps in
Sony digital Betacam machines this morning.

The 'vertical from horizontal' description is pretty poor. Vertical
like horizontal is part of the composite sync. First sync is recovered
from the video and then processed to extract the H and V components.
This can be done with counters and PLLs or simple RC networks.

G²