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So I have a G4 500 Titanium Powerbook that learned to play dead about a month ago. It no longer will start up at all and there is no light, no noise no nothing. I have taken the battery in and out multiple times to no avail. I've tried the hard/soft reset...nothing. I even bought a new motherboard and it still doesn't work. I tested the power button and it appears to be making a connection to the mainboard...but still...nothing.

Any ideas what part would be causing this?

If you replaced the motherboard inside "correctly"..... then likely you want to check out the power supply. Try and get a loaner from someone else. Make sure yours works on another lappy if you can. Aside from that it might be time to sell it for parts and play Taps.

I'm going to fix this laptop no matter what (even if it means replacing every internal part besides the hard drive)..

I have 4 power adapters and none of them work (although all 4 are yo-yos which didn't come with the PC)..

I've tested the board and it IS getting power...just not working.

I take it the reset button on the back next to the video port doesn't help?

Jesus that right there is some determination! God... reminds me of someone.... hmmmm.... not sure who though...

Anyways. You have to have a method here. Work from the wall socket backwards into the computer. If you're sure you have working power adapters then check the power connector on the board. If the board is getting power, next check the memory, cpu and heatsink. You will have to swap the RAM out with RAM you KNOW to work. Same with the CPU. Then work on the hard drive and video.

If you need anything else, I've never worked on one of these personally but it's all just methodology, and I think you have the general gist. I really do hope you get it up and running.

And for folks reading this, any repair like this you do, has to be METHODICAL. Work from the wall back, it's the easiest thing to do. Check EVERYTHING including swapping ribbon cables if at all possible. Last night I got a small reminder when I swapped my office around. Tried plugging in a firewire drive I KNOW to be good as it worked 15 minutes earlier, and it doesn't get moved off the desk so I know I didn't do anything to break it. Turned out the "neat-o" firewire cable that had a blue led in it wasn't working any more. Sometimes it's as easy as swapping a cable.

Good luck and I'll be watching the thread. Hope all goes well.

Yes I have tried the reset button in the back...

Does the ram need to be in order for the powerbook to turn on?

Yes. Turning it on without any RAM in it can fry the whole thing (trust me, I found out the hard way).

Even worse, if you have the memory installed, but the little trapdoor is not in place, that will keep it from booting as well. Trust me on this one, I lost my MIND thinking I'd destroyed a friend's Powerbook after I'd just managed to fix it be re-seating the RAM.

Fry?! Not once have I come across a computer or notebook that would kill itself for having no RAM installed.

Happened to a PowerBook G4 that I had (for about two months). Turned it on without any RAM at all and it would never go past the gray Apple logo screen (the swirly thing wouldn't come up) and just turn off. Tried everything. I don't think it killed itself, I killed it with my stupidity.

So if there's no ram in it won't even light up or chime?

It'll beep at you and the sleep light will flash.

Beeps three times. I didn't notice the sleep light.

That means that no, or incompatible RAM is installed. May also be an indicator of RAM or RAM slot failure.

Alright I got it working, turned out I needed a new PRAM.

Now the problem is that the battery won't charge and the display is black. It boots up like normal, chimes, and loads up, but nothing after that.

Update: Turns out the backlight is not working. The display is working...just no backlight. All ports in the back work...

Any suggestions on how to fix the backlight and/or battery? There are 2 connections that come from the display to the mobo...which one is for the backlight?

There will be a thin black one with a circular plug on, that's for the AirPort antennas, this is on the right with the laptop upside down with the back of the screen facing you. There's also a pink & white cable which looks like it would be the backlight cable. The cable on the left is the display data cable I think.

Here's a useful picture taken from the ifixit guide for the Ti Mercury PowerBook.

Ok, Thanks!

What about the blue and white cable on the left next to the display data cable?

That doesn't seem to be coming out of the screen so I assumed it was the power switch cable for the top case, since the step before was removing the logic board.