SE/30 Logic Board Video Issue

[smrieck511]

Hi All,

I'm working on an SE 30 with a logic board video issue.

Heres an overview of what (I think) I know so far...

Analog board, CRT and PSU are fine. They work with other SE and SE/30 logic boards and have been recapped.

No video - occasionally displays random dots, static. Then calms down and stays dark.

It chimes. The logic board recap fixed the sound but didnt seem to have any affect on the video problem.

I've cleaned the board with IPA several times.

I've taken the video chips and Video ROM out deoxed, ipa and reseated. There was no sign of corossion on any of the pins of those chips.

UE8 looks reasonably ok.

Continuity is good on all the replaced capacitors.

What should be my next steps? Sorry the video side of repairing these boards is completely new to me.

Thanks for any guidance.

 

[ComputerCompulsive]

I have been using the Matrix in the Macintosh SE_30 Schematics redrawn with Matrix file that CayMac Vintage linked me to work on my battery bombed SE/30. You could check the connections for the data lines and address lines to make sure everything is connected correctly.

In my case everything is toning out but I still get an instant crash on startup (death chimes play) and no video out. I was thinking of trying out my new oscilloscope to check the multiplexers but I'm not sure if there is a guide on what wave forms to expect.

Maybe you should try the same? Check the connections the chips I was listening to CayMac the other day and he said the resistor packs can be an issue sometimes as well but they no longer manufacture those.

 

[smrieck511]

Thanks. I got it all sorted out. Just needed a new UE8.