Powerbook 180 untraceable hardware error

[Vacaneu]

I'm completely defeated, so I'm throwing this out there in hopes of someone more knowledgeable than I am will know what's going on here.

The PowerBook chimes, then plays 8 error tones. No sad mac or error codes appear, just a blank gray screen.


List of things I've tried with this machine:

Cleaning everything with IPA and reseating everything
Tested PSU voltage under load (7.56V)
Ran laptop without the drives
Removed internal battery (2.4V)
Inspected components for leakage and corrosion (none found)
Tried resetting the PRAM multiple times
Among others I cannot remember



I suspect a RAM module on the daughter card failed, but I have no way to test for this nor replace it at the moment.

What's going on with this thing?

 

[croissantking]

Almost certainly a failed RAM chip on the CPU daughter card. Unless you’re able to identify the chip and solder in a replacement, you’ll be looking for another daughter card.

 

[Vacaneu]

Almost certainly a failed RAM chip on the CPU daughter card. Unless you’re able to identify the chip and solder in a replacement, you’ll be looking for another daughter card.

Do you know which pins I should try a resistance test on?

 

[croissantking]

Do you know which pins I should try a resistance test on?

That won’t get you anywhere.

You need to desolder chips and test them off board. Not easy or practical unless you’re equipped to do so.

 

[finkmac]

i'd honestly just swap out the daughtercard. should be able to find another one.

 

[Vacaneu]

I was hoping to not have to throw away a component that may be in short supply just because of one IC but oh well