What's wrong with this 15" AlBook?

[Metuas]

I have a used G4 1.5GHz PowerBook. It has gotten a bit of a screen problem. But it is the most confusing, non-straightforward problem I have ever had with a computer.

Starting about a week ago, the screen flickers and tears and eventually the desktop disappears, leaving a thin white gradienty light stripe around 15mm from the bottom. Sometimes brief flickers will bring parts of the screen back, but usually I have to turn it off or sleep it and move it around some.

It's not a logic board/video card problem, since it works fine on an external monitor. That seems straightforward enough. Apple store guy says it's not a connection issue, since the thing is plugged in, soldered and taped so that it won't come loose. He claims that it's an LCD problem, which I'd be inclined to believe - except that no flickering or tearing or going black happens when it's in FW disk mode or boots off of a CD (leopard install disc). Sometimes it works for hours, often it happens quickly - but eventually it always craps out on me. Now for the real question - what is causing this crazy irregular screen behavior that ONLY occurs when booting from the HD? If I can't solve it, I guess I'm going to have to start saving for a macbook - but I love my PB. I don't want to see it gone (nor do I want to give up the nice big screen :/ ). Any idea what's up?

 

[Firefly2002]

Well that's just weird. The only (probably completely worthless) suggestion I can make is trying a PRAM and NVRAM reset. I can't see that working, but I thought there might be a chance in a million since you say it does work in target disk mode. I suppose you could also try repairing the HDD with DiskWarrior, since that's the only other thing I can think of (as it works fine off another disk), but none of my suggestions really seem related.

But then again, I've never heard of anything like that, assuming it's not just a coincidence that it hasn't done it while in Target mode.

 

[Metuas]

Weird is an understatement. Resetting the PRAM/NVRAM worked, for a while. But eventually it happened again. Now I'm getting remarkably solid performance, but I can still tell it's having problems because it flickered when I booted up (the grey apple screen). I'm thinking of formatting the HD and giving it a 7-pass or something, or maybe getting an iPodFW cable and booting off of that, since all I have are USB drives lying around. But thus far my only problem-free times are when it's not booting off the HD. We'll have to see about external drives. The other thing is, if it's a HD issue, why would it have problems on its own screen but not an external one?

Thanks for the reply though. I'm just as confused as you.

 

[Firefly2002]

Welcome.... happy if it helped in any way. That really is just strange.

It might be the HDD, I guess? Maybe you should take it in and ask them to look at the connection to the monitor, just in case. I feel like it's best not to rule anything out just because it seems to defy logic; since this whole thing seems to defy logic we might as well toss reason out the window.

 

[Metuas]

Is there any way to boot from another mac (my power mac g5 in this case) via firewire target disk mode? I've never tried but it sounds like it should work. That would also let me find out if it is indeed the HDD. If I left it on for a day or so, it would probably be clear what is wrong with it. Today it's had a few issues, but leaving it on for a little while seems to clear it up. Which doesn't enlighten me in the least bit.

However, since it sometimes happens at boot up I doubt it has anything to do with the HD. I guess it could just have been lucky with the FW/CD and less so with the hard drive.

I guess I should just start saving, then. Apple refurb store's macbook is $899.

 

[Metuas]

And weirder still...

I still don't have a "solution" to this, but picking up the right side of the laptop (facing one, while open) and tilting it seems to alleviate the problem, whereas tilting the other side seems to exacerbate the problem. It's getting about 1-2 hours of solid usage before it flips out on me and I have to tilt it. I should call my PB 'etch-a-sketch'.

 

[nephilim7]

if shaking it resolves it it may as simple as a loose wire/connection.