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SE/30 random reboots, then nothing?

Posted by: rbdr on 2024-04-13 13:34:57

Hi everyone,

I'm pretty new to the vintage computing world, and especially vintage macs. I'd like to ask for some pointers on how to investigate an issue.

My SE/30 was working well with no issues when it suddenly started randomly rebooting. Often it happened close to boot, but other times it would happen at random times after a couple hours of otherwise uneventful usage.

It was happening again today and it started happening more frequently, very shortly after boot. I adjusted the power cable and it booted normally, was able to use it with no problem but then after I powered it off it hasn't come back to life.

I was wondering if it could be a power supply issue, but really I don't have enough hardware experience to be able to narrow it down. Any pointers?

If it helps, here's some information on the contents of the computer:
- Stock floppy drive, fully functional
- I replaced the hard drive with a ZuluSCSI
- rom-inator ii
- 32 MB of Purple RAM brand RAM
- A CNET ethernet PDS Card
- A MacBatt CR2032
I opened it up to see if I could notice anything astray, but to my eyes it looked the same as always. When I toggle the power there's a faint click (like when the screen comes on but fainter), the SCSI led flashes once and that's about it, then nothing.

Any help is much appreciated! (Meanwhile I'll try to find someplace in Berlin that might be able to help me with this 😛 since I'm clearly in over my head)

Posted by: obsolete on 2024-04-13 15:59:18

Someone's going to ask, so it might as well be me--have the logic board capacitors been replaced?

Posted by: rbdr on 2024-04-14 02:24:46

Someone's going to ask, so it might as well be me--have the logic board capacitors been replaced?

I’m not aware of any work being done on it before, and I certainly haven’t recapped it. This is what the logic board looks like.

Posted by: Phipli on 2024-04-14 02:40:14

I’m not aware of any work being done on it before, and I certainly haven’t recapped it. This is what the logic board looks like.

Based on the symptoms you describe, there is a chance that your issue is the power supply getting weak with age. We can test for this 🙂 do you have a multimeter?

This said, you have to recap your logic board. The longer you leave it the more damage it does. Recapping is fairly easy, but repairing a board that failed due to not recapping is much more difficult, even for someone with a lot of experience. In the following photo, I've highlighted some things that seem to be the start of capacitor related damage. But in short, all the solder will have been shiny at one point. If you look near the aluminium tin can capacitors (the silver cylinders), you will see the solder is dull and even furry with mineral type deposits on it (which is bad) vs. places far from capacitors are likely to generally still be shiny (unless the board has been stored badly in the past).

Would you be interested in learning how to do this yourself? Or are you not in a position that you feel comfortable with working on a logic board?

The main thing is don't put your head in the sand, or you will not own a working SE/30 in the fairly near future, and sorting it sooner is much easier/cheaper than later. 🙂 Let us know what you're thinking.

Posted by: Phipli on 2024-04-14 02:45:21

Looking at the closeups, the following in particular, this is super urgent. I'm surprised your sound was working. Based on the condition highlighted, I recommend getting it professionally looked at if you don't have past electronics repair experience. This is very likely to require trace repairs.

I see you are in Berlin. We have a few members in Germany and Europe in general (I'm in the UK, so the popularist vote has decided to make postage more expensive between us, plus I'm an emotional wreck from a former high stress job and don't like working on other people's computers because of it).

Posted by: rbdr on 2024-04-14 03:20:30

Looking at the closeups, the following in particular, this is super urgent. I'm surprised your sound was working. Based on the condition highlighted, I recommend getting it professionally looked at if you don't have past electronics repair experience. This is very likely to require trace repairs.

I see you are in Berlin. We have a few members in Germany and Europe in general (I'm in the UK, so the popularist vote has decided to make postage more expensive between us, plus I'm an emotional wreck from a former high stress job and don't like working on other people's computers because of it).

View attachment 72530

Thank you so much for all the advice!

Yeah the audio was working well but good to know it’s urgent. Someone in mastodon pointed me to a shop that might deal with vintage Macs so will give them a call on Monday.

I do want to learn to do it myself, but i have very shaky hands so i’m not confident doing it in “live equipment” just yet, but my goal is to be able to.

I’m pretty sure I do have a multimeter. I’ll have a look for it.

Would a PicoPSU be a good option to replace the PSU if that is the case?

Posted by: Phipli on 2024-04-14 03:36:51

Would a PicoPSU be a good option to replace the PSU if that is the case?

Short answer no.

The original power supplys are pretty reliable (if you have the Sony brand part) and given the condition of your logic board, I now suspect it is more likely the issue.

More generally, the PicoPSU isn't a great solution as while they themselves (the high end versions) can allegedly handle the 100W spec of the SE/30, you need an external 5V power brick and it is firstly, hard or even impossible to find a 5V one that powerful (it would need 20A!) or even 12V (it would need 8.3A), those barrel jacks aren't the best for handling so much power. This said, you're not likely to be using the full amount of power... But the stock powersuplies are good, so no reason to replace them really.

Posted by: rbdr on 2024-04-14 03:44:11

Short answer no.

The original power supplys are pretty reliable (if you have the Sony brand part) and given the condition of your logic board, I now suspect it is more likely the issue.

More generally, the PicoPSU isn't a great solution as while they themselves (the high end versions) can allegedly handle the 100W spec of the SE/30, you need an external 5V power brick and it is firstly, hard or even impossible to find a 5V one that powerful (it would need 20A!) or even 12V (it would need 8.3A), those barrel jacks aren't the best for handling so much power. This said, you're not likely to be using the full amount of power... But the stock powersuplies are good, so no reason to replace them really.

Good to know! I'll try to find a professional in Berlin that can help me out but this has been very helpful.

Posted by: Mk.558 on 2024-04-14 21:43:41

I've got the same thing going on with mine.

3D printed programmers switches; Random SE/30 reboots

I'm getting random reboots on my SE/30. The power supply has been fully recapped, the motherboard was recapped some time ago, the ROM SIMM has had the contacts reflowed yesterday so now it actually boots. Power supply voltages are fine. No visibly damaged traces or anything abnormal. Any...

68kmla.org

I've got some old solder in the usual places like below the RAM banks, and some fuzzy solder in some other areas, but nothing like near your sound chips.

It actually boots now that the solder on the ROM slots was refreshed, but I'm kind of in the dark for the rest. Makes me a bit irked because it's the most convenient thing to whip out and test something real fast for my "Life Work" project versus pulling out the VGA-HDMI adapter and all that work.