What are the symptoms of various video issues on an SE/30 logic board?

[smrieck511]

I'm trying to understand video issues more clearly.
I have an SE/30 board and it chimes and seems to boot, but there is no video output. Occasional static, but usually just completely dark. No simasimac just a blackout with occassional static (see attached video).

It is my understanding that if the video ROM was bad, there would be at least something on the screen.

Is this complete blackout a symptom of a bad UE8 or nearby chip? UE8 and corresponding video chips have all been cleaned, look pretty good and there is continuity to all of the vias.

Tested on a known working analog board and CRT so it is definitely confined to the logic board.

Just trying to understand this more clearly before I start removing/replacing chips.

it's been recapped, and all of that seems OK. continuity checked.

Thanks for any information.

 

[obsolete]

The system bongs, right? I think I recall reading that in your other thread, but it's an important data point.

 

[smrieck511]

The system bongs, right? I think I recall reading that in your other thread, but it's an important data point.

correct yes it does chime after the recap so that did fix the sound for sure.

but yeah, basically video blackout before and after the recap.

I bought it pretty cheap on eBay as for repair, hoping it was something on the analog side but yeah logic board video issues are unchartered waters for me. Learning....

 

[obsolete]

Right, and that also confirms RESET isn't being held down.

I don't know what else to tell you. I'd replace UE8, but I am guilty of shotgunning parts sometimes. Perhaps someone else can chime in with some better reasoning.

 

[smrieck511]

Right, and that also confirms RESET isn't being held down.

I don't know what else to tell you. I'd replace UE8, but I am guilty of shotgunning parts sometimes. Perhaps someone else can chime in with some better reasoning.

oh yeah, I didn't think of hitting the reset button. I'll do that just to confirm that it restarts and that is working.