Powerbook G4 hardware issues

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iMac 2.5Ghz, iPad 2, Powerbook G4 Alum.
Hi all. I have a 12" Aluminum Powerbook G4 1.5 GHz, 512 MB RAM, that has two issues currrently keeping it out of working order, and I'd like to be able to get it working again for a family member who doesn't need a newer computer.

1) The screen is completely dark, but you can still make out screen images and print in light, especially sunlight. From what I have read online, this is a problem with something called an inverter, with which I am not familiar.

2) Whenever I boot up, even if I try to boot up from the install disks, I get an "invalid memory access" message.

I have a new memory module on the way to make it smoother, so I'll be able to try it out with that soon, but I also don't believe it's the replaceable memory that's the problem, because when I remove it, I still get the invalid memory access message. From what I've read on this issue, it seems this can be due to problems with on-board memory, video memory, or the logic board. Unfortunately the issue is not covered in sufficient detail in any thread I've found so far. I guess what I'm looking for is more of a detailed walkthrough to determine what the problem is and what I can do to fix it.

Thanks,
Netherfox
 
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I should mention too that my system clock appears to be set to the year 1904.
 

pigoo3

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Your Powerbook has some serious problems. Sounds as if you have an inverter problem. The inverter board is a long rectangular PCB under the clutch cover in the display assembly. This Powerbook isn't as easy to work on as the 15" and 17".

If the date and time doesn't stick after entering, it won't be the PRAM battery, as this Powerbook has similarities to the iBooks, no PRAM battery. They use a very high value capacitor soldered to the logic board that will hold a charge just long enough to save settings while you change a battery. If your main battery is shot or not fitted you will lose date and time when disconnecting the power adapter. See Portable Computers: Models Which Do Not Have a Backup Battery.

Your error message sounds as if the have a defective logic board.
 
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Thanks for the responses. I received my additional 1GB stick of RAM and added it, I'm still getting the same message so it's not that. Process of elimination I suppose.

I was thinking about it. I think the time got reset when I tried to reset the PMU a couple of weeks ago. I had forgotten I tried that so maybe there's nothing to it other than that.

With that in mind, is this still likely a logic board issue?
 

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