SE/30 screen shimmers violently, intermittently

[caver01]

Quick status of the system:
Logic board recapped, UE8 replaced, at least one trace from SCSI chip (D31) repaired with a bodge wire, ASC removed, cleaned, re-soldered, no-leak battery but replaced with CR2032.
Analog board connector (J1? the one that always gets hot and melts/discolors)—had cracked solder joints—reflowed these. Replaced fan.

The mac is working fine now, but it has been a long road of learning and troubleshooting. However, all throughout this process, the screen has occasionally exhibited a horizontal shimmer. When it happens, the display width contracts slightly, horizontal lines wiggle very quickly. I think I hear some static noise while this happens for a second or two, then the image snaps back clean and solid.

As I mentioned, this has been going on from the beginning, so I think my troubleshooting to get the mac working again has neither created, nor corrected this problem. I suspect it is still some issue I have yet to correct and add to my list of accomplishments! How’s that for taking the right attitude?

So, what’s going on here? I have not reflowed the entire analog board—yet, but I also am considering recapping it. I could also look at the CRT neck board or the PSU, though power tested OK at one point. Thoughts? It does seem to be getting more frequent now as I begin to “use” the mac more (reinstalling the OS, connecting to AppleTalk to transfer files, RaSCSI etc.). Attaching a video:

View attachment FullSizeRender.mov

 

[Johnnya101]

Video isnt working for me? Usually a jitter is a PSU problem (at least in my case), but if you are hearing snapping, and it is getting more frequent, it is kind of sounding like a bad flyback transformer. If you take the back case off and use it in a dark room, look for arcing coming from the flyback.

 

[caver01]

Quick status of the system:
Logic board recapped, UE8 replaced, at least one trace from SCSI chip (D31) repaired with a bodge wire, ASC removed, cleaned, re-soldered, no-leak battery but replaced with CR2032.
Analog board connector (J1? the one that always gets hot and melts/discolors)—had cracked solder joints—reflowed these. Replaced fan.

The mac is working fine now, but it has been a long road of learning and troubleshooting. However, all throughout this process, the screen has occasionally exhibited a horizontal shimmer. When it happens, the display width contracts slightly, horizontal lines wiggle very quickly. I think I hear some static noise while this happens for a second or two, then the image snaps back clean and solid.

As I mentioned, this has been going on from the beginning, so I think my troubleshooting to get the mac working again has neither created, nor corrected this problem. I suspect it is still some issue I have yet to correct and add to my list of accomplishments! How’s that for taking the right attitude?

So, what’s going on here? I have not reflowed the entire analog board—yet, but I also am considering recapping it. I could also look at the CRT neck board or the PSU, though power tested OK at one point. Thoughts? It does seem to be getting more frequent now as I begin to “use” the mac more (reinstalling the OS, connecting to AppleTalk to transfer files, RaSCSI etc.). Attaching a video:

View attachment 36797

here is a gif version in case the video did not work for others

 

[Johnnya101]

Oh wow that's really bad.

Does it have a mechanical hard drive installed? Does the screen do that when you hear the HDD accessing info or while using the floppy drive or randomly?

 

[joshc]

I assume by J1 you mean the yoke connector, I always start there, I think its P1 on SE analog boards. Reflowing that one can solve these sorts of issues. Also worth reflowing all the other power connectors on the analog board. Failing that, I'd also make sure the analog board has been recapped. A photo of your analog board would be good in case there's something obvious visually that someone may spot.

It's worth checking voltages under load - is your PSU recapped and giving strong, stable voltages or are they fluctuating? Even a recapped PSU at this point can be weak - some people are converting them to use ATX power supplies.

 

[Byrd]

Another vote for the (4 pin analog board) yoke connector - pull it out and you'll probably see one or two of the pins heavily corroded from arcing, trace these to the other side of the analog and and you'll see more trace damage. Every single SE, SE/30 I've fixed recently has had an element of degradation around the yoke cable. One SE FDHD in particular the heavy copper trace was unrepairable and I had to run a thick gauge copper wire from one of the yoke cables to bypass this trace.

Also when reflowing try to suck up as much of the old solder as you can and replace with fresh.

 

[caver01]

Yes, I did mean the yoke connector. More than one of the pins had cracked solder, so I reflowed all of them a long time ago.

Tonight, I did it again and reflowed every pin of every connector on the analog board plus many others. I have not recapped the analog board, so I should collect the parts and add that task to the backlog. I also reflowed the solder connections on the yoke board itself.

I think this has bought me some time—after doing the above, it booted fine without a single shimmer like before. Now, maybe once in ten minutes I get a slight wave, but it is almost like an optical illusion, as though my eyes are playing tricks. Did that right edge move ever so slightly? hmm. i think it did. Anyway, this is MUCH better now. I would say rock solid if I wasn‘t so sensitive to it. I need to recap though. Thanks for the suggestions!

 

[caver01]

also, @Johnnya101 it used to have a physical drive, but i pulled it to setup RaSCSI. The shimmering happed at random whether the HDD was installed or not.

 

[smrieck511]

Yes, I did mean the yoke connector. More than one of the pins had cracked solder, so I reflowed all of them a long time ago.

Tonight, I did it again and reflowed every pin of every connector on the analog board plus many others. I have not recapped the analog board, so I should collect the parts and add that task to the backlog. I also reflowed the solder connections on the yoke board itself.

I think this has bought me some time—after doing the above, it booted fine without a single shimmer like before. Now, maybe once in ten minutes I get a slight wave, but it is almost like an optical illusion, as though my eyes are playing tricks. Did that right edge move ever so slightly? hmm. i think it did. Anyway, this is MUCH better now. I would say rock solid if I wasn‘t so sensitive to it. I need to recap though. Thanks for the suggestions!

I'm having a bit of this issue with my SE/30. Did reflowing the analog board solder points fix this? I'm planning a full recap and to replace the J1 connector. Hoping its not the flyback transformer.