Repairing SE/30 battery acid damage... what's on D1 and D2, and crystal speed?

[olePigeon]

Coming along.  Gave it a bath and scrubbed it with baking soda, hopefully neutralized the acid.  The solder pads are completely missing for D1.    I can see where the traces are for the top and left pad, but not the right pad.  Not sure how I'm going to fix that.  Resoldered all those tiny chips, too.  Acid got into the ROM SIMM socket, so I'm going to have to replace it.  I'm hoping the PDS slot is clean.  Can't tell... I just don't want to replace it. :-/

 

[olePigeon]

I also cleaned and retinned the pads on the ROM itself.  The acid had eaten the contacts down to copper, but it took the solder just fine.

 

[techknight]

The big thing is going to be patching all the dead vias/open connections. 

 

[olePigeon]

I don't know where the hell this pad goes.  I've scratched away most of the PCB and I can't find any other trace.  Anyone have any idea?

View attachment 4899

 

[unity]

If its a diode, it may not go anywhere.

 

[Elfen]

Its a diode, part of the startup/battery/PRAM circuitry. The third pad goes nowhere.

oldPigeon - hope this helps:

I verified it with my SE/30 board.

What worries me is all that corrosion on the chip and other areas. They can be part of the problem.

 

[Elfen]

Not to Spam the board...

Managed to get a ID number off the crystal on my SE/30 board. It is: S3238E

Cant seem to get a frequency for it on Google. That number is linked to a lot of other things, including some part on a Lexus Automobile. Jeesh...

 

[olePigeon]

My googling came up with 32.768 kHz, which is what I replaced it with.

Unfortunately it still doesn't boot, so I may send it to Uniserver.  I don't have the tools to check traces or anything.  I did what repairs I could based on a visual inspection.

 

[techknight]

As I figured