68kMLA Classic Interface

Is it the same error every reboot/reset? This link (https://udcf.gla.ac.uk/~gwm1h/Error_Codes/Sad_Mac_Codes.html) provides a breakdown 68k error codes, with some specifically for the Portable further down the page. If I'm reading it right, the error you show indicates a RAM test failure at Bank A.

Don't jump ahead just yet. There are a few things you could try first. If you have a RAM expansion card, verify it's in the correct connector (J11) - happens to everyone. You could try starting both with and then without the expansion card. After that, I'd examine the onboard RAM near where you were recapping to see if there is any residue or damage. I don't know offhand what banks are where, but start with a visual inspection.

Also make sure to do a power manager reset if haven't been.

Did you try without the expansion card as well?

This thread might be helpful:

Interesting - seems wildly un statistical that three suffered RAM Sad Macs after a recapping....did you do any board soak/clean as well ?

In the absence of any other obvious path I'm going to pull the onboard RAM, test each chip and see if there are any duds. Nobody seems to be able to point to Bank B which I think the code references - they seem to be divided into an upper and lower (4x4 block) so I don't know if that makes the block nearest the hybrid chip bank B. But given there were replacement caps up near the I/O ports, that might well be bank B....

Like I said elsewhere, I'm only doing this because I failed my crochet practical....

I came across someone on the FB 68K group who mentioned they ran into the same RAM Sad Mac code after recapping when before there was no issue. The only other common link appears to be the soaking/cleaning of the boards, which may have been a good idea in theory but in practice kicked us in the shins. Or higher.

A friend of mine suggested that thermal expansion differences in the VIA plating and the PCB may have caused cracking and as a result some of the VIAs are not connecting properly and may be signalling a RAM error (or something else if the POST check actually was able to continue). While I have the onboard RAM pulled off the board, I'm going to be proactive and examine/fill any open VIA just because. I console myself with the thought that some restorers of old classic cars spend years on the tasks. I guess patience is a virtue as they are my machines and not someone else's expecting it back....

The likelihood of this scenario being correct in the normal sense is remote. But anything is possible. 

If this were to be true, it would likely be due to vias that have already been damaged by the capacitor leakage to begin with, in which case, would have already been a ticking time bomb. I have soaked/washed so many different boards using a couple different methods, and even do it during manufacturing of boards, and never had an issue "except" in areas that were already damaged by leaking caps. 

How long should the board be soaked and with warm or cold water?

Well I typically just either use an ultrasonic cleaner for a few minutes, or use a dishwasher through its quick cycle. Nothing special. 

I don't "soak" boards in a bin or sink because it can cause corrosion due to long exposures to stagnant water. 

Oh any recommendations if I don’t have both? I did soap cleaning with toothbrush but it doesn’t work.