Advice on what to replace?

Hi

Hope someone can help with this, done hours on searching without success.

Just purchased (very cheaply) a Powerbook G4 15" Ali. Problem is the screen is dead, totally black, nothing. On start up I just get the one chime, as in normal boot noise.

I've done all the usual stuff with resets of Pram, PMU, start up pressing R etc etc. but still nothing. Reseated RAM, still nothing.

Have replaced hardrive with one from similar machine, nothing.
Have inserted OS X disc into drive, just spits it back out after about 15 seconds.

Obviously something not right with it, but not entirely sure what it could be and what to replace first. Could the logic board be faulty eventhough I can still manage to switch on, get a chime, insert disc etc? Inverter board has been suggested, not sure where this is located though, part of the logic board at all?? Could it be purely a failed screen?

At odds really as to how to attack this with regards of replacing what first.
Any ideas/solutions anyone?

Many thanks

Dex

Sounds like a bad screen to me. Does it light up or anything?

As todd51 suggests, it could very well be a defective display or the GPU may be dead. Hook an external monitor to the machine and see what happens. If the external works, we can go from there. If it doesn't, you've narrowed the problem down.

Regards.

Hi, screen it totally blank, nothing showing at all. I will try hooking it up to external monitor/tv but will need to purchase a suitable cable first. Will come back with result.

Many thanks for the replies.

Dex1275 said:

Just purchased (very cheaply) a Powerbook G4 15" Ali. Problem is the screen is dead, totally black, nothing. On start up I just get the one chime, as in normal boot noise.....
At odds really as to how to attack this with regards of replacing what first.
Any ideas/solutions anyone?

Click to expand...

Honestly, the first thing I would replace is the entire computer.

It will cost as much (or more) money to repair it as it would to simply replace it.

Fair comment, but as said it was very cheap and until I know for sure what the problem is and how much to put right I may as well run with finding out first before off loading it. Mobo's for these things cost a lot less than the equivalent Dell, was prepared to take risk, just needed some advice I guess before taking the plunge and then afterwards finding out it's the screen.

Dex1275 said:

Hi
Just purchased (very cheaply) a Powerbook G4 15" Ali. Problem is the screen is dead, totally black, nothing.

Obviously something not right with it,

Click to expand...

Like you said...obviously something is not right with it...that's why you got it so cheap!

I don't know that exact specs on your computer...but it's worth about $350..if it was 100% functioning. A replacement screen will cost at least $250-$300 if not more.

The only way you get this fixed without sinking a ton of money into it (if the screen is bad)...is to find another broken computer cheap...with a good screen.

Good luck,

- Nick

Dex1275 said:

Mobo's for these things cost a lot less than the equivalent Dell,

Click to expand...

Can you post a link supporting this?

Macintosh parts are almost always more expensive than the equivalent Dell or other Windows computer. Simple rule...supply & demand.

There are many many more broken Windows computers out there than broken Mac's to get parts from.

- Nick

Can you post a link supporting this?

Macintosh parts are almost always more expensive than the equivalent Dell or other Windows computer. Simple rule...supply & demand.

There are many many more broken Windows computers out there than broken Mac's to get parts from.

- Nick

Click to expand...

Well not specifically but I purchased a Ti logic board around 12 months ago for £60 and previous to that a Pent 4M mobo for Dell Inspiron which cost £140. So a bit of difference in my experience certainly.

Well I hooked it up to a monitor and still nothing appears on the screen, so have to assume here that it is indeed the logic board that's at fault. The hard drive spins up though and get caps and num lock lights on keyboard but deffo no display. Have tried different hdd from another powerbook but still nothing.