Hi. I have been having issues with this laptop for a while now. I bought it to fix it up but am not able to so far. It is a powerbook g4 and I have replaced the bottom case, 2 new chargers, battery, cd drive, extra ram, and the screen is now giving me issues. I never have had the screen work fully so I am not sure about anything.

The screen appears very faint / dark. And now my story....

--I bought an inverter and that did not fix my problem so then I went to buy a ccfl bulb (same kind) and that did nothing (actually I could not even get the ccfl bulb to light up for some reason, I did have to resolder but all the joints were fine...). I gave up with that and bought a new screen.

--With the new screen it sounds like the same issue, very dark.

I am thinking like before when I said the bulb would not light up, what could prevent that? Is there something on the mobo cause I do not think its the screen anymore.

Any help is Thanked!!

Have you tried connecting it to an external monitor to see if you get the see symptom?

F1 and F2 should control the screen brightness! Have you tried them?

Yes I have done an external monitor and that works fine. The f1 and f2 does not do anything (that would be funny tho if I forgot the brightness keys $150 later...).

If F1 and F2 do nothing then perhaps the keyboard is faulty?!?

No, it works fine. And I tested the voltages to see if anything was going to the plug to the ccfl bulb, one is reading I think it was 2v and the other was 1vish?

That does seem rather low. I will have a look in the workshop to see if I have one lying around to test the voltages on.

I might be able to test again if that is to low, because I was just looking around. But if its low what can I do? I have $300 into it and I would like to sell it soon. But this is just strange.... Any ideas you want me to try?

I'm thinking you may have a motherboard fault. Problem is, replacing it is gonna be very expensive indeed! DO NOT try testing the output voltage of the inverter. It could ruin your DVM and give you a very painful shock.
I have a colleague who knows a lot more about Mac's than I do. I will have a word with him and see what he says.

ok. Thanks.

Have spoken to him, he says if it's not a faulty keyboard then it's a faulty motherboard.

Faulty mainboard just to lite the ccfl bulb? Everything else works, I was even on it for a while on the external screen. Anything you think I can do?

Try going to the apple link

What version are you using. If a powerbook is the same as a macbook maybe i can help you. Reasemble the parts again follow the instructions in the apple guide book. be more specific in your problem. Like whether the powerbook freeze during startup or you see a flashing question mark sign or the screen is dark but it is not in sleep mode

version of software?

Are you talking about all of this?
Make sure that the power cord is plugged into a working wall outlet, and that it's properly connected to the power adapter. To check that the wall socket is working, plug in a lamp or other electrical device.
Make sure that the power adapter is properly connected to the power port on the back of the Mac.
If your Mac is a portable, check that the brightness of the built-in display is not set to "0."
Reset the Mac's parameter RAM.
On an iBook or PowerBook, reset the computer's PMU. For an Intel-based Mac, reset the SMC.
If video is available remove display-related preferences:

Delete the com.apple.windowserver.plist preferences located at /Library/Preferences/com.apple.windowserver.plist and ~/Library/Preferences/ByHost/com.apple.windowserver.xxxx.plist/
There may be multiple com.apple.windowserver.xxxx.plist files in the ByHost folder. The xxxx will show as a series of letters and numbers. Delete them all.
Once the preferences are removed, reset the PRAM

You are starting to confuse me. You said that your powerbook light is very dim but can it still login and use?

have you try changing the battery your battery might be a bit old

I have bought a new battery (1 cycle on it so far) and basically a new everything else.

What do you mean by that. Is your problem solved or the lights are still very dim?

I mean what I have been saying.... Everything but the board has been replaced at this point and the screen is dim.....

Then try replacing the motherboard

Yup. I bought a motherboard today and I will wait for it to arrive!

After you insert the motherboard tell us what happen. Did it work or not. If it did not work you will have to let an expert have a look at it. Good luck

I should get it tomorrow. If its wrong there is no money to have an expert look at it... Its going to be chucked out a window at that point and get 100,000 views on youtube in a year. But after the mobo the only things that have not been replaced is the hard drive, keyboard top thing, and a couple of components that would not effect it but I mean I have replaced EVERYTHING....lol

Just a thought, did you replace the ribbon cable that goes between the screen and the laptop? They sometimes break down and cause problems.

No I did not. But with the new screen it came with the back, bezel, and ribbons and etc (and it had same issue).


I was having issues with the power now (trying to charge it or have it run on just dc power) so I had it running on the battery that I had left and now that is dead. I thought I read somewhere that some file was messing up the lamp in the OS and causing it to have issues?? But I am not sure how that file would. I even tried a new hard drive in it but had no luck as the laptop would not start when the battery died?

Should I contact apple support?

I don't think apple will bother with such an old version of macbook. You might want to purchase the newer version of macbook. There is macbook pro and others. Some files have corrupt your hard drive. Crap!!!!

I think i just gave you the wrong advise. It might be a hard drive failure. Either your friend or you keep tilting the powerbook. Apple products are very fragile and their hard drive will crash if you enver handle it properly. TO handle a laptop properly close the screen down and wait for a while until you know it is in sleep mode. When it is in sleep mode, you can carry the laptop around as the hard disk had stop spinning carrying the laptop around when the hard disk is stil spinning will cause the hard disk to crash. Don't buy a new hard disk Try to borrow a hard disk from anyone, and test it on your powerbook. If their hard disk work and you are able to start up and see the screen that means your hard drive crash. You can either buy a new hard disk for your powerbook or chuck it out of the window and purchase a newer version. i would recommend macbook pro if you want

Look I repair computers as I know how to carry one around...I have new hard drives to test. As the old hard drive would before. If you have followed the other parts of this thread I have said it runs perfectly on an external screen.

I am going to call the local mac shop and see what they think about repairing it. And it is not for myself. I buy/repair/sell so its not like O let me go out and waste $2000 on a laptop that I can get for $300 without the apple logo...

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.