Possible Dead screen on Powerbook g4?

Hey all

I've got a 12'' 1.33Ghz Powerbook G4, and basicly one night when i was using it, the screen suddenly went blank. I Rebooted and nothing happens.

Since I've tried to reboot it and i get chimes but nothing on the screen It does boot into Target disk mode, which suggests to me that the Logic board it fine

I've tried to Reset, PRAM,NVRAM and all of those things, and all of them do the correct number of chimes ect.

Any ideas?

I'm hoping for this to be an Easy fix, as this iBook G3 isn't gunna keep up with me soon

I'm perfectly fine with performing the repair inside the machine if needs be

Thanks guys!

Simon

You need to narrow down the cause: Either the LCD panel failed or the GPU is defective.

Can you run an external monitor with it? Also, you said the machine works OK from Target disk mode. Does that mean you can boot it from another machine using a firewire connection but the screen still doesn't light?

Regards.

chscag said:

You need to narrow down the cause: Either the LCD panel failed or the GPU is defective.

Can you run an external monitor with it? Also, you said the machine works OK from Target disk mode. Does that mean you can boot it from another machine using a firewire connection but the screen still doesn't light?

Regards.

Click to expand...

I've got no way of testing it with a monitor.

It boots into target disk mode but nothing shows on the screen. But i can see the do stuff on the Hard Disk.

SimonB said:

I've got no way of testing it with a monitor.

It boots into target disk mode but nothing shows on the screen. But i can see the do stuff on the Hard Disk.

Click to expand...

There should be a video-out port somewhere on the computer.

Chris H. said:

There should be a video-out port somewhere on the computer.

Click to expand...

There is, but i have no adaptor

SimonB said:

There is, but i have no adaptor

Click to expand...

That's kind of my point. Adapter's are easy to find at electronic parts stores- especially online.

There are times where when we try to troubleshoot things, there are certain things a user needs for better help on a particular topic. Getting that adapter is up to you. What we're trying to figure out is if the GPU is at fault.

Im in the UK My friend And the Mini DVI adptors that Fit the 12'' are pricey. Looking at 25/30 quid which is around 45USD

UPDATE-

Sorry i forgot that i had tested it on an External screen, and nothing showed up.

The machine boots fine into target disk mode, and if i let it boot on the HD i can get the Sound Hotkeys to make the little Bob noise. So it boots fine.

It can't be the Backlight as nothing on the screen shows at all.
I don't think its the LCD cos if it was just the LCD the backlight would just shine bright White.
Don't think it can be the reed switch as it boots normally.

Any other Suggestions?

I'm hopings its the DC-to-DC board or the Inverter or a Cable

Help?

SimonB said:

UPDATE-



It can't be the Backlight as nothing on the screen shows at all.
I don't think its the LCD cos if it was just the LCD the backlight would just shine bright White.

I'm hopings its the DC-to-DC board or the Inverter or a Cable

Click to expand...

So you're saying that you don't see anything on the screen even without the backlight on?

What if it is both the LCD and the backlight? Then your assumption that it being the DC board would be correct. Since nothing is showing on either an external or the built in screen I would say you're right on the inverter as well.

Check things out if you're experienced, otherwise talk to an Apple Store or authorized Apple Repair Store.

It sounds like the GPU may have failed. Target Disk mode only means that your hard drive is OK. Since you can not get anything to display on an external monitor (wish you had stated that at first) it could very well be a failed graphics processor unit. The GPU is soldered (surface mounted) to the logic board. Which means if it is the GPU that failed, the entire logic board must be replaced. An expensive repair.

Either way, it may be time for you to consider purchasing a new machine as repairs could certainly cost you more than what your G4 is worth.

Regards.

Chris H. said:

So you're saying that you don't see anything on the screen even without the backlight on?

What if it is both the LCD and the backlight? Then your assumption that it being the DC board would be correct. Since nothing is showing on either an external or the built in screen I would say you're right on the inverter as well.

Check things out if you're experienced, otherwise talk to an Apple Store or authorized Apple Repair Store.

Click to expand...

Neither the LCD or Backlight show(Visibly). So i hope it is the DC-DC Board and/or the inverter.
Is there anyway i can check the voltages? I've got access to all the test equipment i need. But i can't really spend money on a part unless i'm pretty sure it will fix it. I'm a student just trying to get my machine fixed I'm on an Ibook G3 now and it just can't keep up.

I really hope this is't the GPU...

The Machine power's up and Boots fine, just doesn't show anything...

I really hope this is't the GPU... The Machine power's up and Boots fine, just doesn't show anything...

Click to expand...

Better keep your fingers crossed then, because if the machine power's up at all it's not the DC input board... And, I wouldn't bet on it being the backlight or inverter either. Even if it is, that means an entire display replacement since it's very difficult to change out just the backlight. Apple recommends changing the entire display and so do other professional repair centers.

Let us know....

Regards.

Could it not be the DC-To-DC board?

If it is gone, how much could i get for it as spares/Repairs?

BUMP!

Any other ideas?

my G4 Ibook is alos doing the exact same thing. I had it sent in to GPU Medics for repair, and it worked perfectly for like 3 days then i got the black screen and gave up on it. just pulled it out of the closet today and was thinking about trying to revive it being it's in great condition and is perfect for what i need for just web surfing and emails & stuff.

i've been searching online for over an hour trying to find resolutions to try and fix it myself, all i've been getting is "get a macbook" or "upgrade to something newer" but nobody has actually provided any useful info as of this time