Power Mac G4 Won't start up, at all.

[hedpuk]

Hi Folks.

I have a PowerMac G4 400hz. Tried to turn it on, the light flashes white for a second, the fan inside spins but nothing else happens. The disc doesn't seem to be spinning although there is a red LED on on the board.

I've tried replacing the disc with no result on any of them.

If anyone has any clues or has experienced this problem any help would be much appreciated.

Thanks

Glenn

 

[Ric]

Hi there Glen and welcome !

When you say you have changed drives, do you mean the hard drive ?

Has the cable become unseated ?

Sounds like we could reset the Logic Board, and then try it.

Try reseting the PMU first...

Read the doc carefully before doing...

http://docs.info.apple.com/article.html?artnum=95055

regards

Ric

 

[hedpuk]

Hi Ric,

Thanks for the reply. yeah I've changed hard drives incase it was a drive problem with no luck. I'm about to reset the PMU see what happens there. I've also just read somewhere else that if the video card is broken the hard drive won't spin.. so thats also whwere the problem may lay... any way heres to restting the PMU.. I'll let you know the outcome.

Thanks again

Glenn

 

[hedpuk]

Forgot to mention too.. theres no boot tone either.. just a single falsh of the on button, the fan spins then thats it...

Glenn

 

[hedpuk]

Hi.


Just reset the PMU, still no boot up tone. The fan still spins but no noise from anything else.

May see if i can get hold of a cheap graphics card see if that does the trick.

Glenn

 

[Ric]

Have you changed the RAM ?

If you are getting now startup chime I would first check all connections, take out any additional RAM.

Then the next step would be to check the PowerSource with a Mulitmeter...

Did anything happen, before it died ?

Will it boot from a CD ?

regards

Ric

 

[hedpuk]

Hi.

Yeah i've tried it with just one stick of RAm in, the CD tray also won't eject so can't get it to boot from a CD. Only just bought this mac so no idea if its ever worked before, i got it real cheap in the hope that it was salvagable.. where theres mac theres hope!!!

I'll try what you said about the power source and let you know.

thanks again.

Glenn

 

[Ric]

Was it bought as 'dead' ?

The fault finding procedure...

Check the power supply, whip it out and replace with a known good supply.

If it works, it works.

If not, then it would be a logic board replacement.

Sorry !

regards

Ric

 

[hedpuk]

Hi Ric,

Yup Bought Dead. Although the guy said he thought it was just problems with the video card and didn't have time to fix it. Would it be possible to use any AGP video card to test it? or does it have to be apple specific video card?

The fact the CD tray doesn't eject bothers me a little, maybe suggesting no power getting that far.

I mat try replacing the power unit from another G4 later this afternoon.

i didn't have much hope for it before but now i kind of determined to get it working.. !!!

Cheers

Glenn

 

[Cory Cooper]

Go

Did you try replacing the PRAM battery? G4 Macs won't do much of anything if the battery is dead.

Just a thought...

 

[hedpuk]

hi.

I took the battery from a working G4 and put it in, although this may not be good enough. I'll get hold of a new one and check that out too.

thanks

Glenn

 

[Ric]

Did you try replacing the PRAM battery? G4 Macs won't do much of anything if the battery is dead.

Just a thought...

Good idea !

I took the battery from a working G4 and put it in, although this may not be good enough. I'll get hold of a new one and check that out too.

That would work. The battery you took out would enable it to boot if all else was well !

Next step swap the Powersupply !

regards

Ric