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Backwards progress with SE/30

craig1410

Well-known member
I strongly recommend that, once you have a bootable machine, you check whether or not your serial ports work. Both the serial transceivers in my machine looked completely fine but had in fact been tanked by capacitor juice. Again, replacements are cheap and readily available.
I don't want to hijack the thread but I repaired a battery bombed SE/30 a little while back and everything works except I can't boot into system 6.0.8 without getting an error relating to "Responder" which I believe is an Appletalk extension. I also can't boot into 7.5.5 as it hangs during the bootup progress bar at around 15%. I also get errors related to the modem and printer ports if I use the "Snooper" diagnostic tool.

So, this all points to a serial issue. However, I have tried replacing the 8530 SCC chip, the two SN75175 differential receivers and one of the 26LS30 differential drivers. I also replaced the RP2 and RP3 resistor packs which were shorted on some lines. The remaining 26LS30 seems to be working so I didn't bother replacing that last chip but maybe it's worth a shot? Was it the 26LS30s that you replaced or something else? Did you see any weird symptoms like mine?

Thanks.
 

ironhalo

Active member
Replacing UE8 on an SE/30 is pretty much par for the course. I replaced all the chips in that row just to give me peace of mind. These chips are not expensive or hard to find so, in my opinion, it's worth replacing them just to be on the safe side. As mentioned: you really can't see the extent of the damage caused by the old caps.

I strongly recommend that, once you have a bootable machine, you check whether or not your serial ports work. Both the serial transceivers in my machine looked completely fine but had in fact been tanked by capacitor juice. Again, replacements are cheap and readily available.

Best of luck with your repairs and nice job so far!
Thanks for the guidance, much appreciated. In preparation to preemptively order some replacement chips while my board dries out this week, I've made a spreadsheet of all the components that have visible corrosion (or were simply adjacent to the leaky caps). I seem to have located Mouser part numbers for everything except:

1) UB10/UB11 (Sony 3430045B) sound chips - I assume these were custom chips Sony made for Apple. Are there viable replacements of any sort out there?

2) UE10 / ASC (VLSI 344S-006301) - Same as above. Maybe a better question though is are these sound chips commonly found to be bad when they have visible corrosion on a portion of the legs?

2) UD12/UE12 (the 26LS30 line drivers) - they come up in Mouser's catalog as obsolete. Do their modern equivalents go by another name?

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claanu

Active member
IMHO, before you go ordering replacement chips, I'd start by going over your work a second time. If it was working before the recap, and got simasimac after the recap, chances are your issue lies somewhere within the bounds of those 13 capacitors.

You've done nice clean work, but a number of solder joints look cold. If I were you, I'd go over each cap, suck up the solder with some good copper braid, and then add new solder using your flux of choice. Use a bit more heat than last time. Probably not necessary to remove the caps entirely, just suck up as much solder as you can and add new stuff.

I'm also a bit concerned by the damage on either end of C11. That cap (and the traces underneath) is often a problem area.
 

caver01

Well-known member
your situation is very similar to my SE30 restore. i also replaced UE8 and the rest of the chips in that row. over the course of months i saw my video get progressively worse until i had black “jailhouse” columns AND simasimac. UE8 was the culprit, but i also had a poorly seated ROM simm. Pulling it and carefully cleaning it and the contacts, then putting it back eliminated simasimac once i had replaced UE8. This was after weeks of continuity testing every connection on the video schematics.

For the sound, i had residue and corrosion UNDER the ASC chip. I removed the chip with chipquik alloy, cleaned everything and put the chip back—twice. i then had distorted audio and non-working SCSI which turned out to be a bad trace somewhere for D31 between the scsi chip and the CPU. fixed it with a bodge wire and this cleared up the audio too which was probably also failing because of the same broken data line.

these things are a labor of love. I say stick with it for sure. i had to put my SE30 away for 9 months out of frustration and fatigue, but i came back to it and found the faults. you will too!

as for the other recap work, i agree that it makes more sense to proceed stepwise. case in point, after fixing the above, i moved on to recapping the analog board and PSU, but this created additional setbacks for weeks. I had old solder joints, possibly a faulty resistor, P1 connector issues, and the PSU was shorting the 12v rail to its chassis—all of this as a result of my recapping work. you don’t want so many potential issues at the same time. Had i recapped everything at once and started troubleshooting the logic board, i never would have been able to find success and multiple simultaneous faults would have been almost impossible to figure out. My mac would very likely be on a shelf or in a recycling center by now!
 

ironhalo

Active member
IMHO, before you go ordering replacement chips, I'd start by going over your work a second time. If it was working before the recap, and got simasimac after the recap, chances are your issue lies somewhere within the bounds of those 13 capacitors.
Solid advice and I felt the same must be true, unfortunately since my original post i’ve already reflowed all the capacitors and some of the corroded chips nearby, cleaned the board with alcohol again, and again checked the capacitor connections by verifying continuity through their respective traces/vias. No luck after that. I’m going to follow others’ suggestions by giving the board a very thorough cleaning and some agitation with soap and water today, but i’m only so confident that’s going to fix my issues entirely. On top of that, the sound has never worked, and at least one of the rear ports never worked (maybe more) so i’m fully expecting other components may be bad in addition to the caps.
 
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ironhalo

Active member
I'm also a bit concerned by the damage on either end of C11. That cap (and the traces underneath) is often a problem area.
Yeah it does look pretty bad there, but i buzzed out all of the traces in that area and they seem okay.
 

ironhalo

Active member
Had i recapped everything at once and started troubleshooting the logic board, i never would have been able to find success and multiple simultaneous faults would have been almost impossible to figure out. My mac would very likely be on a shelf or in a recycling center by now!
Point very well taken. I’m holding off on any further recapping til I get a handle on the logic board issues. Glad you were finally able to ferret out your issues!
 

superjer2000

Well-known member
FWIW I have never done this, and it hasn't made any difference at all.
Agreed. If the PSU was working before and it’s still showing the right voltage it doesn’t make sense to blame the PSU and analog board at this stage. It seems pretty clear the issue is related to the logic board recap and the analog board/PSU is a red herring.
 

ironhalo

Active member
Agreed. If the PSU was working before and it’s still showing the right voltage it doesn’t make sense to blame the PSU and analog board at this stage. It seems pretty clear the issue is related to the logic board recap and the analog board/PSU is a red herring.
Thanks for weighing in. I'm currently focusing on a really thorough cleaning of the board, and replacing at least 2-3 of the most corroded chips adjacent to C2/C7. If no forward progress still, I'll likely remove and resolder some/all of the new caps.
 

ironhalo

Active member
I seem to have located Mouser part numbers for everything except:

1) UB10/UB11 (Sony 3430045B) sound chips - I assume these were custom chips Sony made for Apple. Are there viable replacements of any sort out there?

2) UE10 / ASC (VLSI 344S-006301) - Same as above. Maybe a better question though is are these sound chips commonly found to be bad when they have visible corrosion on a portion of the legs?
Regarding the above sound chips, how common is it for these to go bad due to corrosion or age? Can they still be sourced?
 

ironhalo

Active member
Back with an update. Was waiting to take delivery of a new stereo microscope before resuming work on this one. Happy to say I'm booting nicely once again, and have working audio for the first time since acquiring this machine! Huzzah!

Once I got my new scope installed, I spent a lot of time examining the areas around the capacitors as many folks suggested. Underneath two of the caps were traces that had been slightly exposed by corrosion, and I believe at least one of them got some solder paste on it when I installed the new caps, creating a short. I cleaned everything really well, covered up those two traces with solder mask, and reinstalled the caps. That was enough to get me booting again. However I was having so much fun using the new scope I decided to address some other areas of significant corrosion. I ended up replacing the entire row of 7 chips from UA8 to UG8, as well as RP1 and UA9. That seemed to have gone much smoother than the original recap process (likely because I can see what I'm doing SO much better with this scope!)

I still have a few issues to address, but will likely start a separate thread or two for those. Thanks again to everyone who helped point me in the right direction!
 

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mdeverhart

Well-known member
Woohoo! Stereo microscopes are awesome for this kind of work. We have them at work, and it’s amazing what a difference they make. Glad you got it working!
 

ironhalo

Active member
Woohoo! Stereo microscopes are awesome for this kind of work. We have them at work, and it’s amazing what a difference they make. Glad you got it working!
Thanks! Glad to get it back up and running. Yeah it’s truly an incredible difference from the 4x magnifying lens I was using. Amazing how much better your soldering looks when you can actually see what you’re doing!
 

ironhalo

Active member
How much does one of those cost??
I got mine from Amscope with the articulating arm mount for around $600, but they have cheaper options. They had one unit on sale with a simple table top stand for under $400. It’s a decent amount of money, but now that I’ve experienced the difference I wish I’d gotten one years ago.
 

craig1410

Well-known member
How much does one of those cost??
I got a Swift S41-20 which cost me £179.99 delivered in the UK. It's got a fairly simple mounting arm which is a bit of an annoyance at times but I'm quite sure I could buy a better arm for it if I wanted to. It comes with a pair of 10x and a pair of 20x fixed focus lenses but I've only ever needed to use the 10x for electronics assembly work. It also has a pair of lights on flexible arms so you can direct the light exactly where you want it. Here's a link to Amazon if you want to take a closer look but while I'm very happy with the value for money of this unit, I think in retrospect I should have spent a bit more money to get the articulated arm and possibly variable focal length.
 
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