Quadra 700 with battery damaged logic board

[Swolfington]

I recently picked up a Quadra 700, and unfortunately the battery had leaked a little bit onto the logic board. Can anyone take a look and see how bad it appears? I've never dealt with this kind of stuff before, but it doesn't appear too bad? I got it off ebay, and the auction said it powered up (they had a picture of it with the green LED lit), but I haven't dared to even plug in the power. it looks like it lost a couple of SMD bits for sure, and clearly the battery connections are a complete wash. The battery case was completely disconnected (rattling around the case when I got it home) and the metal contacts were completely gone. I saved the plastic battery holder just in case, as the plastic didn't seem to be too worse for wear. The SIMM closest to the battery has some corrosion spattering, but it doesn't appear to have completely eaten away through anything..though my hopes aren't high on bringing that one back to life I suppose.

Sadly, what saved everything else was the the machine must have been upside down, because the entire underside of the floppy drive is rusted through. It was so bad I couldn't even manage to unscrew it from the drive bay because the corrosion has filled the screw head to the point that I couldn't get a driver in there.

On the plus side, there was a PPC upgrade card and a radius videocard, seemingly untouched by the battery juice. 

I've attached a few key pictures, and here's an album with some more stuff https://imgur.com/a/DBBsy

Thanks!

 

[Compgeke]

As far as battery damage goes, it's far from the worst. I'd suggest cleaning it up and seeing how many traces are damaged. You'll need to desolder the ram slot closest to the board as well to clean under it and replace it.

 

[Bolle]

This looks totally fixable.

I had boards that looked worse but dis not even have a single broken trace after removing all the rusty goo.

It depends a little bit on how long it has been sitting around. Vias will be eaten away first amd eventually it will male its way through the solder stop mask and eat away at traces if given enough time.

 

[Alex]

Clean with 99.9% isopropyl alcohol. It actually doesn't look too bad. Once cleaned up, including under the RAM slots as suggested, you will have a better idea of what should be done. Post pictures again after the cleanup if guidance or a second opinion is needed.

 

[Swolfington]

So I actually tired to clean up the board a few weeks ago, and got most of the residue off.. but upon closer inspection there was still a lot of gunk between the pins of some of the chips (especially bad was that VLSI chip just south of the whole disaster area). I finally got some time again today for a more thorough scrubbing, and I am feeling better about it. I ended up using a toothbrush and 99% isopropyl alcohol (which was surprisingly difficult to obtain.) I did not, however, remove the SIMM sockets; my soldering skills/tools just are not there, and I am optimistically hopeful the damage isn't too bad under there anyway - no battery goo appears to have gone under the sockets.

The overall damage looks about as bad as it did before; C65, D6, the battery holder itself, and the power LED are gone. R78 is still intact for what its worth, but it looks pretty grungy. That aforementioned VLSI chip still has continuity with the board, but the pins do look pretty bad. A lot of the solder joints on the surface mount stuff look dull, and most other exposed metal has become corroded to some degree (the closer to the battery out gassing, the worse), but I hope most/all of that is just cosmetic.

My question is, would it be a terrible idea to try to run it in this condition? It looks like the majority of the damage was done purely to the battery, and a cap and diode that dealt with the battery. I probably wouldn't even be running it with a battery in here anyway, so would there be any problem just leaving it as-is? The missing power LED is annoying, but that's a through-hole mount and if i had a replacement LED I'm sure I could replace it; but even without I wouldn't think that would affect anything else..?

 

[joethezombie]

Those components are for the battery backup.  It would be fine to try and power it up.

 

[chickenplucker]

If you are worried about any potential remaining corrosion, a bit of baking soda in warm water with more scrubbing will help neutralize any acid that may be left on the board. Prolly won't help with the looks of the spill, but should keep any green fuzzy's at bay.

 

[techknight]

I think the biggest issue is the RAM slots may have been damaged so youll probably get sad chimes. 

 

[Swolfington]

After cleaning it again (and giving it a baking soda water scrub, then rinsing again), I put it back together.. and amazingly, it works! The hard drive does not boot, I am not sure if that's because it's been wiped or just so old it gave up the ghost. The drive sounds..good-ish I suppose? It spins up, I can hear the heads click, but I am not very familiar with what a hard drive of this vintage is supposed to sound like on a good day. I can't boot it from floppy, because the floppy drive it came with was definitely ruined (I didn't bother taking any pictures because it's almost a solid block of rusty hot garbage. it really took the brunt of battery leak, for better or worse). No sad chimes, even with all the original ram, the video card and CPU upgrade card installed. just the startup sound and a blinking question mark floppy, waiting for a disk that wont ever come. Honestly i'm pretty pleased it got that far. 

Next step, i'm going to steal the floppy drive from from my Mac IIVX and try to boot it from from that. Does anyone know if It would be possible to plug in an internal CDROM drive (which would also be gratefully stolen from the IIVX) in the q700 using the internal scsi bus? It clearly wouldn't physically fit in a long term solution roll, but just to get some software up and running it would be handy to have a temporary cd drive option.  

 

[Compgeke]

If you've got a long enough cable you can. With a double connector cable and a molex splitter you could even do hard drive and cd off the internal connector, just can't mount the CD.

 

[Swolfington]

Awesome, thanks for the info! My Q700 actually has two molex power connectors; I thought the floppy drive used one, but apparently that is not the case! I wonder if someone replaced the cable at some point?

I took out the floppy drive from the IIVX, and annoyingly the drive sled/cage thing is different. The original one from the quadra is rusted to hell, but maybe it's salvageable. Since it's just a hunk of metal, I can take it out and sand all the corrosion off. Blegh, it's such a mess though.

 

[Swolfington]

I managed to partially install system 7.5 on an external Jaz drive! The hard drive it came with technically seems to work, but it appears that some/most of the data on it is corrupt. I can see the files, but I tried copying some of the more interesting stuff to the jaz drive and like every 4th file could not be read. [side note, it looks like this machine was used for graphic design in the mid-90s. I love the time-capsule aspect of bringing old computers back to life!].

I say partially installed, because the installer refused to read "install disk 1" at the tail end of the installation process. The disk itself must have been working, because that was the disk that booted and started the installation process. Even tried imaging another floppy, but it just refused to budge. At that point I just restarted the machine and hoped for the best. Thankfully it booted, but some stuff is missing (everything from the apple menu at the very least, which is mildly annoying).

However, it was enough to check the RAM.. and sadly, it appears that the RAM slots are dead. No matter what configuration of the SIMMs I try, the only thing that shows up is the 4 megs built into the logicboard. I even tried some known good RAM from the IIVX I've been stealing all the other parts from that are making this project possible, and they don't show up either. I am kind of surprised, since if there were something wrong with the RAM slots, I wouldn't expect the machine to even boot? if it were missing/broken/shorted pins, shouldn't it be causing problems beyond just not showing the RAM? So far it seems to operate just fine, as far as I can tell.

The lack of ram is going to be a problem doing anything even remotely useful with this thing, though. I think I'm at a standstill until I get brave/stupid enough to desolder the RAM slots and see what I can see there.

 

[Bolle]

There clearly is corrosion on at least one of the RAM slots. The contacts on the first one look like they are green in one of the pictures. You can try to fix that with vinegar but RAM or ROM slots I have seen with this kind of corrosion have all been toast so far.

 

[Byrd]

Good to hear you got some life out of it, Swolfington - I picked up a 7100/80 recently, and came across similar battery explosion nastiness around one of the RAM slots. If you see corrosion on the top of the RAM connectors, the acid has leeched up through the socket and not a good sign.  You might need to source a replacement 30-pin RAM socket for it if keen.  I cleaned mine extensively and never did get a single sign of life on mine.

 

[Swolfington]

@Bolle yeah, there is definitely some corrosion on the tips of the contacts in that last RAM slot. From the outside, it looks like only the tips were affected (where the ram was actually seated seemed to be alright), but clearly something is worse than it looks since none of the slots work at all. I haven't tried vinegar yet, I will give that a shot before I get brave enough to remove the slots entirely.

Thanks Byrd! My hope/theory/complete shot in the dark was that the corrosion on the RAM slots was just from battery outgassing, since a lot of the exposed metal around the area (but not in the direct path of disaster) had become tarnished..but evidently hope was not enough to fix everything.

I guess what surprised me the most was that the computer otherwise seems to function fine. I would expect that if there were something physically messed up with the RAM slots I would be seeing a sad mac icon. Does anyone know if there a separate controller chip that handles the SIMM RAM separately from the built in RAM that may be damaged as well?

 

[Compgeke]

It may just be that the power lines or something aren't making contact so it's not even recognizing there's something in the slots. It's hard to tell without removing them to see what's going on. Unfortunately finding replacements can be a bit more difficult, I'm not sure if anyone still makes 30 pin simm connectors but asking around on marketplace here you should be able to find someone willing to suck a few out for you.

It seems you're a bit worried about removing the slots though. If you want my advice, it's equipment upgrade time. Pick up a ZD915 or similar ~$100 desoldering gun and it'll make easy work of those. As long as you don't shove hard and scrape the tip on the board, or set it to something insane like 400*C, it's more difficult to do damage.

 

[Swolfington]

Thanks for the name of the tool. I'll check it out! Just did a quick search on Ebay and found this auction that looks at first blush like it could fit the bill. It says "2.54mm pitch", which I assume means the distance between the pins? I'll have to remove the logicboard and measure them to see how it looks. The price isn't bad either!