SE/30 Board Mystery Issue

[smrieck511]

just tested an SE 30 board with an issue issue I have not seen before.

The board itself looks very clean. I took out the 1989 battery so that might be a clue that nobody has worked on it before.

Capacitors show very little signs of leakage and the chips don't look corroded.

Now the bad news. There appeared to be something that looked like water damage on the underside of the board.

and the worst news. No sound or video output.
occasional intermittent static on the CRT that looks like snowflakes.

I got this for a good price so if I just bought spare parts for my working SE 30, so be it. It would be nice to get this running though.

I'm gonna start by soaking the entire board in IPA in hopes that that might clean out any liquid inside the board although, it wouldn't repair damage so maybe a waste of time.

Thanks for any wisdom.

 

[Phipli]

Photos of both sides, reall high resolution ones in good light, would be an excellent start. A closeup of the area I've highlighted too if you can

 

[smrieck511]

also, I am testing this on a known, good working analog board and CRT.

 

[smrieck511]

Photos of both sides, reall high resolution ones in good light, would be an excellent start. A closeup of the area I've highlighted too if you can

View attachment 72421

OK will send more Hi-Rez ones shortly. Thanks.

 

[finkmac]

my reply to your previous thread: https://68kmla.org/bb/index.php?threads/another-se30-risk-on-the-way.47164/#post-528706

also, first things first... clean and recap

 

[bibilit]

Hi, board doesn’t look bad at first glance, but i see a bit of corrosion on the battery area (near C12)

 

[smrieck511]

so what I'm wondering is could failed capacitors cause total video failure? You'd think this thing would have the courtesy to give me a simasimac.

if that is the case, I will certainly feel encouraged to recap it.

 

[davewongillies]

Bad caps can definitely be the cause of no sound, I had the same problem on a Mac SE/30 recently. Replacing caps C3 through to C7 fixed it.

Console5 sells cap kits for the SE/30. Here's the cap kit for the logic board.

 

[smrieck511]

Bad caps can definitely be the cause of no sound, I had the same problem on a Mac SE/30 recently. Replacing caps C3 through to C7 fixed it.

Console5 sells cap kits for the SE/30. Here's the cap kit for the logic board.

yes, for sure sound but I was not aware that bad caps could completely take out video… I was thinking that had more to do with bad UE8 and stuff over on the video side

 

[smrieck511]

Photos of both sides, reall high resolution ones in good light, would be an excellent start. A closeup of the area I've highlighted too if you can

View attachment 72421

 

[Phipli]

There are a couple of suspect looking traces there, especially around UD12, and next to UE10.

Best to remove all the caps and then inspect and check the continuity of any bad looking traces. Best to do with no caps on the board so you can inspect the traces under the caps. Once you've repaired any broken traces... Search against 3 more times for the ones you missed. The more stuff you catch at this stage by careful visual inspection, the less difficult things will be later.

Then recap and test the machine.

 

[Phipli]

Here are some of the things that I'd want to check out if I was you, just in a first pass of the first photo. Lots of dark traces showing corrosion got under the solder mask. Seems to be happening next to pins a lot rather than in open space.

 

[GRudolf94]

That board looks clean in the same sense that I look like Jennifer Aniston, I'm afraid. You have a fair few crusty vias and things that look like broken traces next to ICs. At a quick glance here's some areas that very clearly show corrosion.

 

[smrieck511]

Here are some of the things that I'd want to check out if I was you, just in a first pass of the first photo. Lots of dark traces showing corrosion got under the solder mask. Seems to be happening next to pins a lot rather than in open space.View attachment 72437

Thank you SO much. I appreciate it.

 

[smrieck511]

That board looks clean in the same sense that I look like Jennifer Aniston, I'm afraid. You have a fair few crusty vias and things that look like broken traces next to ICs. At a quick glance here's some areas that very clearly show corrosion.

Haha ..ok Thank you so much for taking good look. I'm learning.

 

[smrieck511]

That board looks clean in the same sense that I look like Jennifer Aniston, I'm afraid. You have a fair few crusty vias and things that look like broken traces next to ICs. At a quick glance here's some areas that very clearly show corrosion.

Haha ..ok Thank you so much for taking good look. I'm

 

[Phipli]

@CompactManiac These photos are worth looking at for a clue to what you're looking for.

The first two clues are darkened dust where it has got slightly wet from electrolyte. Then you see how the solder is dull instead of shiny? That isn't an age thing, it means corrosion, even if it is just from poor storage.

Then, looking closer is the very worrying thing, where the traces almost vanish from view just before they reach the pads, that is where corrosion has got under the solder resist at the pad and worked back up the trace. Some will still conduct, but you need to scrape the solder resist off to inspect them and some will need tinning, others will need a little bodge wire.

This is how small show-stopping issues can be. All people that haven't dealt with it before believe that their boards are in good condition because they're looking on the macro and not the micro scale, and the issues are... Sort of micro. Hard to see.

 

[smrieck511]

@CompactManiac These photos are worth looking at for a clue to what you're looking for.

The first two clues are darkened dust where it has got slightly wet from electrolyte. Then you see how the solder is dull instead of shiny? That isn't an age thing, it means corrosion, even if it is just from poor storage.

Then, looking closer is the very worrying thing, where the traces almost vanish from view just before they reach the pads, that is where corrosion has got under the solder resist at the pad and worked back up the trace. Some will still conduct, but you need to scrape the solder resist off to inspect them and some will need tinning, others will need a little bodge wire.

This is how small show-stopping issues can be. All people that haven't dealt with it before believe that their boards are in good condition because they're looking on the macro not the micro scale, and the issues are... Sort of micro. Hard to see.

got it, if the issues are all top level stuff on the board, I feel reasonably confident with the repair work. if something bad is going on the inner layers of the board of course it's game over for me.

 

[Phipli]

got it, if the issues are all top level stuff on the board, I feel reasonably confident with the repair work. if something bad is going on the inner layers of the board of course it's game over for me.

You'll be fine most damage is on the surface and vias can usually be easily bypassed. The best tool you have for repair is your eyes. Spend the time inspecting every pad and via and you will see anything that looks nasty, then you can check it with a multimeter. I think we have multiple schematics for these. A reproduction board with minor changes, but will open in tools that will highlight traces for you, as well as Bomarc (not a huge fan) and possibly also Apple schematics (their early revision schematics and there is a change, but that is documented in the reproduction).

 

[joshc]

That board looks clean in the same sense that I look like Jennifer Aniston, I'm afraid.