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

 

[croissantking]

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

Well it depends, the board is likely repairable but if you can’t do or don’t otherwise have access to the SMD rework required then your only option is to replace it with a working component.

Maybe donate it to someone else local who can repair it rather than throwing it away?

 

[Vacaneu]

Well it depends, the board is likely repairable but if you can’t do or don’t otherwise have access to the SMD rework required then your only option is to replace it with a working component.

Maybe donate it to someone else local who can repair it rather than throwing it away?

Will look into this potentially

 

[Vacaneu]

One more thing, what chips are compatible with the system? I know pb 170 chips are, but what about pb duo or 500 etc?

 

[croissantking]

One more thing, what chips are compatible with the system? I know pb 170 chips are, but what about pb duo or 500 etc?

PB 140/145/170 chips are too slow - those are 100ns whilst you need 85ns or faster.

You can grab the chips from any PB160/165/165c/180/180c or RAM cards designed for them.

 

[Vacaneu]

PB 140/145/170 chips are too slow - those are 100ns whilst you need 85ns or faster.

You can grab the chips from any PB160/165/165c/180/180c or RAM cards designed for them.

I'm assuming the 70ns 210 duo chips will work then?

They're the only ones that wont cost 100$ to get

 

[croissantking]

I'm assuming the 70ns 210 duo chips will work then?

They're the only ones that wont cost 100$ to get

No, they won't. The 210 uses DRAM, the 1x0 uses PSRAM.

You can get the needed chips from the models I listed.

 

[Vacaneu]

No, they won't. The 210 uses DRAM, the 1x0 uses PSRAM.

You can get the needed chips from the models I listed.

I see. Thanks for the help, and sorry about the dumb redundant questions. I really appreciate it!