PowerBook logic board woes

December 27, 2005 3:21 PM

Should I get my PowerBook's logic board replaced?

I've had a PowerBook since February of 2004, which came with two 256MB RAM chips. Everything has worked fine until this Christmas, when I got a 512MB RAM chip as a gift. With the 512 installed, I get a kernel panic within a minute of booting up; with the original 256
chips, everything works fine.

A Genius at the Apple store tested the computer with other RAM chips, and the 512 wasn't a bad piece -- the computer won't run with any 512MB (or larger) chip installed. He also tried booting from an external drive (didn't help) and running extensive diagnostics tests off of a CD (no problems reported). He concluded that it's a logic board issue, and that I should mail off my computer to Apple for a $324 repair. WTF?

Does this actually sound like a logic board problem? The Mac Genius seemed pretty confident that it was, but I'm skeptical because he couldn't test for it -- he could only tell me things that weren't the problem. I don't want to send the thing off for expensive, lengthy repairs for no reason. Could it be something else?

Also, can I safely ignore the problem if I don't upgrade the memory, or is my logic board somehow corrupted (meaning that the computer may eventually not work at all, and I should get it replaced)? The Genius was evasive on this question -- presumably because of a vested interest in doing more repairs -- but recommended an "aggressive backup schedule" (which I've begun). What to do?

posted by danb to computers & internet (12 comments total)

I assume you don't have an apple care plan?
posted by qwip at 4:10 PM on December 27, 2005

Nope. Out of warranty, too...
posted by danb at 4:15 PM on December 27, 2005

Get a 2nd opinion from an independent mac store. The kind that's been around forever, people trust to work on vintage macs, and that's populated with old hairy guys that wear tie-dye.
posted by SpecialK at 4:16 PM on December 27, 2005

Most computer repairs are done like this - they swap other parts to determine what's not wrong. It's easy to change the ram chips vs. disassembling the whole thing and getting to the motherboard.

You might want to try another genius or another store (although they keep track of CPU/SN# to see what's been done to a particular machine.

Even if the motherboard dies, the Drive should be fine. You should always be doing 'agressive' backups anyway.

Not that will make you feel any better.
posted by filmgeek at 4:18 PM on December 27, 2005

You've tried the 512 stick in both slots, by itself? What about trying each 256 stick in both slots, by itself?

When you press certain keys on the keyboard, does the display go blank (and does the computer go to sleep if you hold them long enough)?

Do you get a bizarre startup sound, interspersed with white noise? Do you get a crash on boot, followed by a few beeps and a flashing power light?

I think you have a different PowerBook from mine, but all of these things happened to me (although I only got kernel panics when there was something in the top slot), and I couldn't figure out what the hell it was (and I also couldn't make it break except when I was alone, so it took weeks of attempts to get it sent to Apple for a warranty repair)—it did turn out to be the logic board in my case.
posted by oaf at 4:19 PM on December 27, 2005

Oh, yeah, I forgot—when I had it sent off, they were nice enough to take the hard drive out and let me keep it.
posted by oaf at 4:28 PM on December 27, 2005

There's a somewhat related trend going on that people are reporting that an OS X update might have possibly damaged their Powerbooks' logic board, causing it to not recognize RAM in the lower RAM slot. See this URL:

https://www.lawyersandsettlements.com/case/apple_powerbook_classaction

Does it sound like a logic board problem to me? Yes. Will Apple fix it or acknowledge the problem? Probably not. But, dig around on MacFixit's forums and MacNN's forums for other people having this or similar issues. I know there are out there--I've seen their posts (but don't have time to dig them up now). Good luck.
posted by mrbarrett.com at 4:30 PM on December 27, 2005

SpecialK:
That's a good idea. Any idea how I could find a store like that? I'm in the NY area, if that helps.

oaf:
You've tried the 512 stick in both slots, by itself? What about trying each 256 stick in both slots, by itself?

The 512 causes a kernel panic, whether by itself or with a 256, in either slot. With either 256 chip by itself, or with both, everything works.

When you press certain keys on the keyboard, does the display go blank (and does the computer go to sleep if you hold them long enough)?

Nope. With the 512 chip installed, the computer freezes almost right away, usually with the kernel panic warning. Pressing keys, moving the mouse, etc. do nothing.

Do you get a bizarre startup sound, interspersed with white noise? Do you get a crash on boot, followed by a few beeps and a flashing power light?

I don't have any of that -- booting up is perfectly normal. In fact, there's no evidence of a problem until a few seconds after the desktop pops up, at which point it freezes/panics. (Incidentally, the Mac Genius asked about the beeping and flashing too, which is another reason I don't 100% trust his diagnosis.)

mrbarrett.com:
Thanks for the link. The problem is similar to mine, but I don't think it's the same. My computer will register memory in both slots (I even managed to get into About This Mac before panicking, and it showed 768MB). Still, I may look into the suit further, and I'll definitely check the forums.

Thanks for the tips, everyone. Keep 'em coming.
posted by danb at 4:49 PM on December 27, 2005

Sounds like a faulty trace on the logic board, and it probably isn't reparable without replacing the whole thing.
posted by cillit bang at 5:12 PM on December 27, 2005

Let me also mention that my problems escalated from random, inexplicable reboots and kernel panics to the computer turning off (when the logic board was flexed slightly by me pushing a key) to crashes before the operating system even loaded. So it's probably not going to get anything but worse and weirder.
posted by oaf at 7:19 PM on December 27, 2005

Any idea how I could find a store like that? I'm in the NY area, if that helps.

The infamous and also lovely Tekserve.
posted by RJ Reynolds at 4:53 AM on December 28, 2005

A friend sent me this today.
posted by autojack at 1:11 PM on December 28, 2005