I have a Sony KV-36FV1 television that has a vertical sync problem.
Most of the time it is ok but every few minutes, the picture jitters up
and down for several seconds. Sometimes the picture will "lock" halfway
down so that the bottom half of the picture is on the top and the top
of the picture is on the bottom.

I've seen service manuals for similar models of televisions. They make
reference to a VFRE option (vertical frequency adjust) in the "service
menu". I think that is what I need to adjust but it doesn't show up in
the service menu for the KV-36FV1. I have tried the following options
but they don't seem to fix the problem.

VSCO VLIN VCOM VSIZ PVSZ VPOS VHRE VHG VAPI VAPG VTRR

Any suggestions???

Landson