Beyond repair?

[fabian]

I picked up a broken SE/30. Opened it and saw a very bad case of battery acid. Cleaned it, but corrosion made some of the legs of some chips fall off.

 

I don't mind soldering and spending time on it, but is it possible to make it run.

 

Before I opened it, it showed horizontal lines.

 

What's the best way to find out if it's repairable?

[aeberbach]

Best way to find out would be to catalog exactly what chips are damaged, and see if you can replace them. Of course you would need to remove those chips so you may as well, and after that you can assess how bad the PCB is, whether pads remain attached to the board, whether holes and vias clean up nicely or how bad it all looks. But going by a quick look, that board is toast. I would be surprised if it could be made to work.

[Garrett]

I have no experience with fixing boards, but it looks better than some others I've seen online. The video ROM, crystal, capacitor and ROM card (especially the connector) looks toast, though.

 

As a side note, it seems like every 1 out of 2 (or 3) SE/30s I've seen has an exploded battery inside. It seems like it's not as prevalent as an issue with other models. Maybe the Classic/Classic II is a close follower, but still.

Edited October 10 by Garrett

[Byrd]

Looks like melted cheese ... you've done a top job cleaning it up.  The biggest concern IMO is the corrosion around the ROM slot, repairing that will be a pain.

[ignatio]

I think its still worth getting out a DMM and doing a continuity test on all the effected pads. It will take a while but I've seen worse damage.

 

I agree however that the ROM slot might make it uneconomical to repair (time wise).

[fabian]

On 10/10/2020 at 7:56 PM, ignatio said:

I think its still worth getting out a DMM and doing a continuity test on all the effected pads.

Do you know of any guide on this? I have used a DMM to check batteries or to see if a cable is connected, but never anything else. When i buy a DMM, is there anything in particular i should make sure it has?

[davidg5678]

You should make sure your multimeter can do continuity measurements. This means that it beeps when the two probes are touching. 

 

I think that this board could probably be repaired. As to whether or not the amount of time, money, and effort required to fix the board are worth it, well, that's another question entirely. You would first need to replace every part that was damaged by corrosion. This alone will probably not fix the computer, though. It is very likely that several of the traces between the different components have been broken, so that they no longer conduct electricity between the parts on the board. You would then need to test literally hundreds of connections between the ICs to determine which are broken, so that you can patch them.  

 

I can confirm that this process is a lot of fun, but I have never been able to actually make anything work again. I have spent many multiples of the amount of money a new board would cost in the pursuit of fixing a broken one. In this monetary regard, it is almost definitely not worth it. As far as fun projects go, that's up to you!

[ignatio]

22 hours ago, fabian said:

Do you know of any guide on this? I have used a DMM to check batteries or to see if a cable is connected, but never anything else. When i buy a DMM, is there anything in particular i should make sure it has?

Make sure it has a symbol like this on the dial and you should be good to go. What you want to do is flip the board over, touch one probe to the first leg of the DIMM slot and follow the trace to wherever it buggers off to, maybe a VIA or another chip leg. Touch the other probe to the destination, if it beeps then the trace is good. If it doesn't beep, the trace is rotten and you'll need to solder a wire from the DIMM to the destination, a small wire would do, I've often used wires from old IDE cables for this purpose and they work fine. I had to do this to an SE FDHD board because of damage to traces around the RAM slots, it boots up just fine now. I don't think it's super important but try to make the wire more or less the length of the trace you are replacing.

 

And as David says, this is a lot of FUN.

 

EDIT: I also just noticed that many of the VIAs on that board are literally gone, as in there is no longer a copper pad or solder filling it, those will all need to be patched.

Edited October 11 by ignatio

[ignatio]

Just looking at one of these images in detail and it may indeed be beyond hope. The visible damage in this picture alone would take many, many hours to diagnose and repair. Many of these traces appear visibly corroded albeit the lighting makes it hard to tell. One way to know if a trace is internally dissolved is to hold the board up to a high powered light, if you see light coming through a trace line then the copper is gone, though this is far from a 100% accurate method. The red lines I highlighted look damaged to me.

 

[360alaska]

I don't want to be negative, but the only board I've ever recovered after a battery explosion is the Mac Classic, the area around the battery for the classic is not nearly as dense. But you have a schematic, check for continuity and go from there.

[LaPorta]

I would remove ALL chips that were in the affected area. I’ve rescued an SE that had just as bad of a blow, and the issue I had was crud that was unseen below chips was shorting traces and corroding things.

 

There’s no way of cleaning under there otherwise. Some you may have to hack out and get replacements.

Edited October 14 by LaPorta

[bibilit]

to be honest i won't lose my time, in my opinion too far gone.

 

I have several of those boards, probably your best issue is to keep an eye for a new production batch of new boards and populate it as far as possible.