Can't get G4 Powermac to Boot - help needed!

I bought a used G4 400 Mac a few weeks ago from a company that was closing - I was told it was working and just needed a HDD and ram. I got a HDD and some Ram but couldn't get the thing to boot - it powered on, the red mobo LED comes on, fan etc but nothing comes up on screen. At first I thought the Gfx card must be dud.

I managed to borrow another G4 800Mhz from my mum's work and just bought some Jaguar discs. Oh, and I also brought home the ADC connected TFT from my mum's work, so the monitor is definitely compatible.

First I tested my Gfx card - put it in the G4 800 and surprise, it works fine, so I stuck it back in my 400Mhz. I then took the ram and battery out of the 800 and put it in mine to rule that out. Stuck in the OS X install CD, turned it on and held "C". Still nothing.

Also, purely as a test measure I got hold of an old 4Gb HDD with OS9 installed on it. Although it doesn't fully load, it does boot up with this HDD plugged into the work's 800Mhz - unfortunately, on mine, still nothing though. I also tried putting the 800's OSX HDD into my 400Mhz, but still nothing :(

Anyone got any ideas?
Thanks

What HDD is it? Try looking at www.xlr8yourmac.com where they have feedback of all sorts of non-official upgrades to apples. Like, seeing if a DVD writer will work in OSX...

What exactly happens with yours - do you get a chime? NOTHING comes up on the screen? Are you sure the gfx card is compatible with your computer? Old G4s only had agpx2 or x1....what gfx card is it?

Even better, list everything you have in the machine. Everything. Name/brand/spec of every bit of hardware.

Hi Dave,

Thanks for the reply :)
The HDD is a 40Gb Maxtor DiamondMax Plus 60 7200rpm (model 5T040H4) - I read about one person on that DB that had a driver problem in OSX with a Diamondmx but I wouldn't have thought there'd be a problem at BIOS level (?). I have another HDD I can try if needed.

Everything else in it is stock - this G4 is AGPx2 I think and gfx card is the Rage Pro 128, the DVD drive is also stock AFAIK. The ram taken from the 800Mhz is HynixPC133 (model hym71v32635hct8-h) - I think the 400Mhz is 100FSB but the Ram should be backwards compatible. There's no other cards.

I get nothing on screen, no chimes but then on the 800Mhz model there isn't a chime when it boots up either...and there's about a 5 second delay before it posts too (i.e. the 400Mhz and working 800Mhz behave exactly the same, showing nothing on startup for the first 5 seconds - the only difference is the 800 then kicks in and boots).

I've only got the loaned G4 for the next few days so I'll need help on this pretty quick - if you've got no ideas, is there a busier Mac board I should try (xlr8yourmac.com maybe)?

Thanks again!

Well, the closest thing to that mac I've ever played with is my PM 9500, or my iBook, so I'm possibly not the best person to ask!!

I'd say try www.lowendmac.com and have a look at the lists (not boards) and see if you get any joy on there. The message lists are pretty active and usually have good tips.

Also, *should* be backwards compatible doesn't mean *is*! Some P3 boards wouldn't take 133 MHz RAM. Have a look on crucial.com/uk, put in exactly your model, and see if it brings up 133 MHz DIMMs or not. *Edit* just looked, should take 133 ok.

I take it you don't live anywhere near me as a last resort??

I guess you don't have a PCI gfx card to try? Thinking it could be the agp slot itsself...

*Edit* you should get something on screen even if the system finds no drives whatsoever - a disk icon and a flashing cursor.

Not sure about the lack of a chime, my iBook (700MHz/summer 2002) makes a chime when I turn her on...

*More...* Have you pushed in the CUDA switch on the mobo? Kind of a reset button which makes the machine re-detect everything, rather than assuming anything. Usually near the cpu card or agp slot I think, have a look on google...

Hi Dave,

Thanks again for all the help - I actually posted this topic about 6 weeks ago and you'd given me some advice then, but I thought it'd be best to start afresh now that I've got the other G4 to test with. Just thought I'd mention that as I've tried most things now!

I'll need to try lowerendmac as xlr8 isn't accepting registrations atm - pitty because there seems a lot of knowledgeable Mac people there. Tried emailing the admin to see if I could register but got no reply.

Ram - I've got 4 dimms here, 2xPC100's and 2xPC133's and none seem to make a difference.

Graphics - Yes, I got hold of an old PCI mac VGA card off another forum but didn't have any luck with that either (though I couldn't rule out the possibility that that card's knackered).

Have also tried the CUDA switch but it didn't help.

http://www.utc.edu/Administration/He...noboot_mac.htm

http://forums.macrumors.com/archive/index.php/t-62603

these are maybe useful, maybe no...try removing the battery for a day or so when computer fully disconnected..

Hi Dave,

Thanks for the links, will check them out (I had tried removing the battery previously though). Oh, and I forgot to mention yesterday, I'm in Glasgow so a bit far from you but I appreciate the offer :)

Goof - did you ever have any success? I've got the exact same problem with the same Mac and tried the same steps without success. ugh! :mad:
-rob