Powermac G4 - Boot Problems

I apologize if this topic has come up a lot, but I have an issue with my Powermac g4

The problem is that when i press the power button, the power light flashes on then goes off. The machine tries to boot up, but the screen remains black. The fans turn on, but nothing else happens. The machine stay will on and the fans running until I press and hold the power button to turn it off.

Not sure what the problem could be or how to fix this.

I believe I have Leopard OS on this machine, if thats a contributing factor.

Thanks!

Firstly, welcome to the forums.

You're right, this topic has appeared a lot, but it's not always easy to find the posts.
Resetting your Mac's PRAM and NVRAM

It ALWAYS helps to post the model and specs of your machine so experienced users can relate their experience in fixing the problem. There are 10 models of G4 PwrMac, which one do you have?

Try resetting the Power Management Unit, or CUDA as set out below:-

Resetting Cuda/PMU on Power Mac G5, Power Mac G4, Power Macintosh G3

Thanks for the quick responses!

I tried resetting the PMU, to no avail unfortunately.

I am unsure exactly which model I have, since I cant turn it on. I do know its 1Ghz Dual and it has the mirrored doors.

The video card is by ATI

It dioes happen at times MDD models will not boot with a flat PRAM battery.

Just a hunch. Do you have a voltmeter there of any kind? If so check the PRAM battery. Should measure 3.6 Volts or close. Seen many G4 system that would not boot if that battery was dead.

I dont have a way to measure the voltage in the PRAM's Battery

Assuming it is the PRAM battery, is that an easy or cheap fix?

Radio Shack can order them and some stores might have it in stock. You can find them cheap on Ebay. Do a search for Mac PRAM battery and see what you find.

There she be:-

http://eshop.macsales.com/item/Newer Technology/BAA36VPRAM/