My first severely battery-bombed Classic Mac... any advice ?

[iPhil64]

Hello all,

A while ago, I had bought a very cheap non working Classic.
I opened it today, to find a very badly battery bombed machine. I haven't extracted the board yet, but think it will be outside reasonable repair, so this will be a good parts source for me.

This is the first time I have so much damage on a machine, and the board won't even slide, as it seems literally glued by corrosion.
Any advice on how to remove it without causing too much additional damage ?

The battery itself, a few capacitors, the quartz just fell of the machine as I was opening it.
The analog board, floppy, hard disk CRT and memory extension look ok, I will test them later.

 

[robin-fo]

My Classic looked the same. It‘s working again, now

 

[iPhil64]

How did you start ? I even hesitate to force the board out, the chassis is si fragile now.

 

[robin-fo]

I used a little bit of WD-40 and bent the chassis slightly outwards.

 

[KennyPowers]

Depending on how many of the custom ICs are hosed, this could be a fun project: https://github.com/kr239/Macintosh-Classic-Reloaded?tab=readme-ov-file

 

[3lectr1c]

That one's really bad. Might be worth doing a reloaded board rather than trying to fix all those bad traces and vias. You'll have to see what it looks like on top after cleaning and scraping the corrosion off.

 

[iPhil64]

Did take the motherboard out.
I already did a vinegar/toothbrush path, now in the ultrasonic cleaner (which is a bit small unfortunately). The board itself does not look that damage at first sight once all the residues are out. Anyway, I do not have a lot of hope.

Depending on how many of the custom ICs are hosed, this could be a fun project: https://github.com/kr239/Macintosh-Classic-Reloaded?tab=readme-ov-file

ooooh yes !

See the "after" picture, not sooo bad, and mostly passives on the left hand side. Worth playing

 

[iPhil64]

@Kai Robinson Hey Kai ! Is there an existing source for Classic reloaded boards, or should I start from the Gerber's ?

 

[iPhil64]

@Kai Robinson Hey Kai ! Is there an existing source for Classic reloaded boards, or should I start from the Gerber's ?

Replying to Myself... MacEffects...
Any other source ?

 

[Kai Robinson]

Just macEffects, off the shelf.

 

[iPhil64]

New board ordered. Analog board will need recap (see bottom left) at least, but not in a bad condition
How do we stop corrosion for good on the chassis ?