Analog board - display horizontal alignment

kaltree

New Tinkerer
Sep 7, 2024
3
1
3
Boise, Idaho, USA
Hello, first time posting but a long time reader. The knowledge share here is fantastic and has helped me save several SE and SE/30s that I keep for my personal use, and I'm so glad to have found this community.

I'm seeing this very strange issue and I'm guessing it has to be some issue with the analog board. I've swapped out several spare analog boards and can isolate the issue to this analog board. No matter the balance of horizontal or vertical adjustments made, I can't get the picture to shift left. This is the closest I could get to maintain overall image size without falling off the right side of the CRT.

I suspect there is a component on the analog board that is having issues and would love to repair, but unsure which component.

Anyone run into something like this?

(also - yes, this has ZigZagJoe's greyscale card - but can confirm that's working great and not the issue)
(edit: forgot to mention this analog board has been recapped)

IMG_6372.jpeg

IMG_6369.jpeg
 
Last edited:

kaltree

New Tinkerer
Sep 7, 2024
3
1
3
Boise, Idaho, USA
Thanks for the link! I'll save that one for sure. Envious of the brand new flyback transformer in that document.

Since I didn't have the issue with other analog boards, I may swap it out with a spare. Something about making live adjustments with those voltage levels spooks me.
 

chuck.dubuque

New Tinkerer
May 21, 2023
12
9
3
I've done it myself twice---once for ZZJ's grayscale board, and once when I transplanted a green CRT into my SE/30. You just really want to pay attention. Usually when I am working on these grand old machines I am not as careful as I would be with a brand new motherboard since $$$, but the high voltage stuff is definitely where you want to slow down, plan, and be methodical. But totally understand not wanting to do it.
 

kaltree

New Tinkerer
Sep 7, 2024
3
1
3
Boise, Idaho, USA
Thanks for the tip - I hadn't adjusted these rings before, but that was definitely the fix. Reading the linked document, I found a 'toot-brush' (actually have a set of plastic electronics adjusting tools) and re-centered the image. Much better now, and now I have another tool in the toolbox.

Any idea what people use to re-glue/anchor the centering rings? Hot glue? Seems like it would be good to either leave them as-is or anchor with something that can be easily removed in the future.
 

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chuck.dubuque

New Tinkerer
May 21, 2023
12
9
3
Hot glue is probably the way to go if you want to fix them. It took a lot of pressure for mine to move so I left them, but if yours are loose (like you are worried it will change if you move the computer), then hot glue and wait a few hours before moving.
 
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