Problems with Quadra 610 ; Dead Board and Unusual PSU

jazzius

Member
I have a Quadra 610 that I recently acquired, and while getting the case cleaned up and ready to go has been fine, for whatever reason, the board is being problematic.

While the Power Supply does need to be recapped, (which I will get to momentarily), it seems to put out healthy voltages, and they don't drop under load, despite the fact that the PSU usually needs a minute to turn on for the first time after being plugged in.

Nevertheless, the board is dead, but in a way I would appreciate advice diagnosing, as on startup, the only thing I get is a speaker pop, a power LED, some heat from the 68040, and LEDs over ADB. But that's it. No chime, display, or disk activity, it just halts. Granted, when I first got this system, it did have some moderately bad cap leakage, all of which I cleaned up, and I already removed all of the caps, but right now with no caps, no gunk on the board, and no visible damaged traces, it's just completely dead. While I do suspect there is a possibly a bad solder pad or lack of a CPU clock signal somewhere, I am not completely sure how to being diagnosing this problem, as a I don't have a visual reference as to where on the board to probe with a Multimeter to start checking for problems, and I haven't spent the time to yet to hunt down a good quality schematic myself for the 610 to figure out where the ultra vital connections actually exist.

Also, as for the Power Supply, I was just going to go somewhere like Console5 for a cap kit for it, but no matter where I look, I cannot actually find a cap kit that caters to my 610's specific PSU, as both the sticker on the outside of the PSU and the silkscreen on the internal PSU boards say it's a "TDK" power supply. No indication anywhere of any part of it being made by Dynacomp or Astec, and nowhere on the internet seems to have any information on recapping this supply from what I can find. In case it helps anybody, the only useful leading information that I could see on this supply is that its Model # is MSE103, and the Apple Part # is 614-0022.

Any leads I can get on this machine would help a lot! I really want to get this one working, especially because this is my first 68040 machine, it's not in too bad of shape, and it's as of now showing at least some notable signs of life, even if they aren't super signficiant.
 

luRaichu

Well-known member
but right now with no caps, no gunk on the board, and no visible damaged traces, it's just completely dead
So you're saying you removed all the electrolytic caps from a logic board, and you expect it to work without them? You have to solder new caps, either polymer or tantalum.
Also, as for the Power Supply, I was just going to go somewhere like Console5 for a cap kit for it, but no matter where I look, I cannot actually find a cap kit that caters to my 610's specific PSU, as both the sticker on the outside of the PSU and the silkscreen on the internal PSU boards say it's a "TDK" power supply. No indication anywhere of any part of it being made by Dynacomp or Astec, and nowhere on the internet seems to have any information on recapping this supply from what I can find. In case it helps anybody, the only useful leading information that I could see on this supply is that its Model # is MSE103, and the Apple Part # is 614-0022.
Who needs a recapping guide? roll your own!
Crack that baby open, count all the caps, and order replacements off DigiKey or Mouser. Perhaps you can write the first recapping guide for this PSU
 

Chuckdubuque

Well-known member
Take lots of photos of the PSU before you take it apart (make sure good lighting, focus, etc) and as you remove components make sure you know where everything came from. I create a grid system with a plastic small parts bin and document which slot (C10, etc.) each component came from and put it there. I write out the value (1uf 100V, etc.) on a sheet. That way I can also double check later if my writing is bad.

Also watch out for any places where the polarity printed on the silkscreens do not match the way they were installed. Make sure you install new components the way they were previously installed. Not everything was well documented back then.
 

jazzius

Member
So you're saying you removed all the electrolytic caps from a logic board, and you expect it to work without them? You have to solder new caps, either polymer or tantalum.
As for the logic board, the reason I was pretty sure I would at least hear a chime without the caps is because I believe with my Macintosh iici, the board would at least try to work without them, but to be frank, this could be poor memory. I think I will just recap it first and see where that lands me. It didn't work before the recap and had the exact same problem, so I assumed that taking them out along with a bunch of cap juice might improve things some.

Who needs a recapping guide? roll your own!
Crack that baby open, count all the caps, and order replacements off DigiKey or Mouser. Perhaps you can write the first recapping guide for this PSU
I was also just considering doing the PSU part myself, but I just wanted to ask the community first to see if there was a tested and working kit for this PSU model before I took any shots in the dark. I have been looking at caps on Mouser recently already to find good replacements, and I think I might just be able to put that part together by myself, because it's pretty basic stuff really.

Just curious though, for a PSU like this one, are there any kind of Radial Electrolytic's that I should hard avoid?
 

luRaichu

Well-known member
Just curious though, for a PSU like this one, are there any kind of Radial Electrolytic's that I should hard avoid?
Personally, I would avoid the Chinese brands and go for anything made elsewhere (i.e. Japan)
For switch-mode power supplies you probably want low-ESR caps. You should see if the old caps are low-ESR.
 

cheesestraws

Well-known member
Just curious though, for a PSU like this one, are there any kind of Radial Electrolytic's that I should hard avoid?
Personally, I would avoid the Chinese brands and go for anything made elsewhere (i.e. Japan)

To an extent, although the made in China isn't so much the problem as the mystery aliexpress brands you've never heard of. Go for a reputable brand like nichicon, panasonic, wurth &c., or the house brand of a reputable component distributor (like RS or Farnell), because wherever they are made they will generally be of decent quality.

Note that in a PSU of this age you might need to care about ESR, so worth checking the ESR of the original caps and matching low-ESR for low-ESR.
 

croissantking

Well-known member
As for the logic board, the reason I was pretty sure I would at least hear a chime without the caps is because I believe with my Macintosh iici, the board would at least try to work without them, but to be frank, this could be poor memory. I think I will just recap it first and see where that lands me. It didn't work before the recap and had the exact same problem, so I assumed that taking them out along with a bunch of cap juice might improve things some.

It’s a fair assumption because the SE/30 will run normally without any caps at all, you just lose sound.
 

Callan

Well-known member
I don't have a 610, but both my 475 and 660av require a pram battery to boot. If you haven't replaced it / installed one that's probably the issue your having getting it to boot. If you've pulled all the caps you'll definetly have no sound and probably other issues too.
That tdk power supply has some weird value caps in it if I remember correctly (compared to most other power supplies that is).
Who needs a recapping guide? roll your own!
Crack that baby open, count all the caps, and order replacements off DigiKey or Mouser. Perhaps you can write the first recapping guide for this PSU
This is how it's done. I can get you a list of the caps if you'd like, but you really want to to get dimensions and leg spacing off the caps too It costs more buying caps @ mouser (unless your buying in bulk), but you know your getting good caps/fast service if you go that route.
 

jazzius

Member
I don't have a 610, but both my 475 and 660av require a pram battery to boot. If you haven't replaced it / installed one that's probably the issue your having getting it to boot.
I already tried this and it made no change. I even tried plugging the machine into a monitor in case the caps were taking away the sound, and there was no activity from what I could tell. I might try another monitor while I wait on my Mobo cap kit though just to be sure it's not a cursed Sync on Green situation or something.

Also, I think I can shop for my caps myself. I have already been in Mouser lately tracking down various values, and I think I should be able to get the sizing and spacing checked if I use my Caliper.
 

jazzius

Member
IOSB chip can be problematic on these, if caps leaked into it.
Actually, I was doing some more inspection of my board recently, and I determined that my problem is some of the connections on the IOSB, however, what kind of bodge wire do you think I would need to buy that would be small enough to make bridges between the legs of the chip and the traces without being too big as to interfere with other legs?
 

fergycool

Well-known member
My first (and only) recap of a logic board was a Quadra 610. Now it's working pretty well and I (still) have not yet recapped the PSU (although it's an Astec one). Unfortunately I'm afraid I have nothing really too helpful to add but I would say:
  • It does not need a PRAM battery to boot.
  • Once I'd recapped I got the chimes of death, but before that when I'd removed the caps and fully cleaned then I did power it up. That showed no sign of life at all.
My issue with the chimes of death was traced to (geddit!) one of the legs of U31 that had been corroded by cap goo. I just added a tiny blob of solder to the leg to bridge it to the via and I got the proper nice chimes! After six months or so working on it it was a real pleasure to hear those, so do stick with it. Good luck.
 

jazzius

Member
You have to solder new caps
I did actually do this, but the board is still dead. However, I discovered that some of the chip legs of the IOSB have completely wrecked pads, and what I wonder is, what kind of bodge wire would be good to bridge chip legs and traces that are that puny?
 
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