Mac Classic logic board with different Sad Mac codes

[nvdeynde]

I've got another troubled Classic logic board. This one is in rough shape due to capacitor leakage before I got it.
The whole board was cleaned, caps replaced and several spots needed overcoating to protect the board. It has worked for several years since then.

Now It's giving me nothing than Sad Mac codes. Problem is that it are different one's.
Most frequent it doesn't chime and gives a 0000000E - 0000F000
Sometimes it chimes and gives 000000F - 00000002 or 00000003 - 00006000

Most of the time it's the 0000000E. However when I move the board on my bench, it sometimes comes to live after pressing the reset switch for a few seconds and then gives a Sad Mac 0000000F or 00000003.

I don't know where to start debugging with these different Sad Mac error codes.
It looks like there are 1 or more bad connection but I haven't been able to find them, especially since these are intermittent.

Any ideas ?

 

[nvdeynde]

If I recall well there was a project about reverse engeneering a Mac Classic logic board.
I saw a youtube video about it a while ago, regretably hadn't bookmarked it and can't find the video again.
It was a completely black PCB that was breefly shown in a repair video of a Classic logic board with a severe battery leakage.
I did wonder at the time why the new PCB wasn't used as so many traces and via's of the original board were just gone .

Maybe it was a still a prototype. Does anyone know more about this ?

 

[shreya892]

Most of the time it's the 0000000E. However when I move the board on my bench, it sometimes comes to live after pressing the reset switch for a few seconds and then gives a Sad Mac 0000000F or 00000003. great. sad dp