[kevinthomas]

I have inherited a PB G4/400 that is experiencing LCD freezes and troubles waking from sleep. I've searched and searched but can't find any similar experiences to help me diagnose the machine. Hopefully someone here can help. Here's a summary of what's happening:

- by itself, not moving it...it pretty much works flawless. But, if I am working on it on my lap and move it to a table, it shut down on me. Just "Poof"...off she goes.

- Yesterday, I had it on and the display went to sleep...it wouldn't wake up. I closed the lid, the hard drive stopped spinning but when I opened it, it still wouldn't wake up. Reboot - went to desktop but the mouse and keyboard wouldn't respond. Reboot - ok...then it wouldn't go to sleep. The mouse/keyboard was responding ok after the restart but then after it sat for 30min or so, no response from mouse/keyboard...they freeze on the screen but the machine is still ok...hard drive and cd work just nothing responds on the screen.

- this is the main problem...it'll be working fine but if you move it, the screen will freeze (mouse/keyboard no response)...

I've read around and it seems it could either be the cable that feeds the screen, a damaged logic board or the inverter board (not sure what that is)....

Can anyone help....pinpoint, suggest, point me in a direction, suggest sites, etc, etc?

Thx!

[Detrius]

I'm leaning towards logic board on this one.

The inverter powers the backlight. If you aren't having backlight issues, then you aren't having inverter board issues.

If the data cable to the display were bad, you would either see nothing at all or really freaking weird stuff.

You are saying that the LCD freezes, but there isn't any information here to support that. You say the keyboard and mouse won't respond, but you also everything works. Do you mean that you still hear the drive spinning, or that when you press the volume keys on the keyboard you hear the volume change? Does iTunes keep playing?

I think you are experiencing hard freezes. In your case, that would basically either be logic board or bad RAM. The fact that it powers off when you move it implies that there may be a short inside the thing somewhere--or that the logic board is cracked and only has a connection when sitting in a certain manner.

Just some ideas here.

BTW, On the TiBooks, a bad LCD cable would be far worse than a logic board. The display assembly is epoxied together, and Apple doesn't offer separate parts that go inside it. Unless you ship it to someone that has the technology to fix this, a bad LCD cable means a new LCD on this machine. However, this doesn't appear to apply to you.