I have one of these that started acting up last night. Pwrs up, has
high voltage, no raster with input connected. I replaced the suspect
optocoupler and cleaned up a bit of cracked solder today. Pwrd it up
with no signal, I got the OSD so I figured it was ok now. Put it back
on the desk and connected it to the pc via the BNC inputs.....came up
for long enough to see the XP splash screen then a relay clicked and
no raster after that. It does still display the OSD when there is no
input.

I don't have a service manual for it....haven't had it that long. Any
ideas?