Power Macintosh G3 Blue&White stopped booting into MacOS 9

[duk1975]

Hello everybody! I have unexpectedly faced with the problem with my old Power Macintosh B&W. I bought this machine in 1999 and upgraded it much: up to 1 Gb memory, Sonnet 800 Mhz G4 ZIF processor upgrade card, ATI Radeon 7000 PC flashed video card, DVD-RW super-drive and Sonnet PCI IDE controller card, for native IDE controller in my revision A mobo may work with the drives up to 10 Gb capacity only. So the machine worked perfectly and even in real life tests was (and I hope is) equal to G4 Quicksilver boxes.

I boot the machine not very often. Yesterday I discovered that it unexpectedly stopped booting into MacOS 9.2. I choose the MacOS 9 partition to boot, the machine rebooted and there were no happy mac appeared. Just the grey screen. The same happened when I tried to boot with MacOS system CD with “C” button pressed.

To the Tiger 10.4.11 it boots however, but some resource intensive tasks go to the screen of death.

I tried usual ways of reviving: PRAM reset, memory out one by one, even native 350 Mhz CPU installing back. All PCI cards were out and I tried to boot from ZIP drive or CD. Tried native ATI Rage 128 video card reverting. After all nothing helped, but the machine stopped booting even to Tiger until I moved video card from 66Mhz PCI slot to 33 Mhz.

What it can be? Help me, please!

 

[davecom]

It does sound like you've tried almost everything. Are you able to get into open firmware? Have you tried the standard open firmware commands:
reset-nvram
set-defaults
reset-all
More here:

Mac Classic

Tips and tricks to help keep your Mac OS 9/Early Mac OS computers usable today. Software downloads, guides, hacks and news.

mac-classic.com

That's the only "standard thing" you didn't mention that I can think of (a firmware issue).

Otherwise my guess is you are dealing with some kind of failing logic board issue or failing RAM. Did you try just some of the RAM on its own? Any leaking capacitors? These are just guesses. At first when you said Mac OS 9 was not booting off CD or HD but OS X was, I suspected the flashed video card. But it sounds like you've tried every possible combination of hardware... so that leaves only a failing "centralized" hardware component like RAM or the logic board it would seem...

You may want to try booting into one of Apple's Hardware Test CDs if there is one for your model.

 

[mikes-macs]

Have you tried to boot from another drive? It may be failing boot drive.

 

[techstep]

I hope you are able to get to the bottom of this with your current board, but given that you have all of the other upgrades already, you could always source a replacement Rev 2 board pretty inexpensively!

 

[davecom]

Have you tried to boot from another drive? It may be failing boot drive.

He said he tried booting from CD.

 

[mikes-macs]

He said he tried booting from CD.

Apologies, missed that.

 

[Byrd]

With all the CPU switches - pressed the CUDA switch on the board?

Rev A boards are fine, nothing unreliable about them apart from the IDE slave issue.

 

[duk1975]

Thank you guys for your answers. Try to reply.
1. I didn't try open firmware reset yet. Will do it tomorrow
2. There are no capacitors on G3 B&W "Yosemite" mobo. At all. At least I didn't see anything that may look alike.
3. Sure I tried every RAM on its own and even got new bank of 256 mb RAM
4. May it be power supply? There could be leaked capacitors, I didn't take it apart yet
5. After all can it be the mobo fault?

 

[davecom]

Thank you guys for your answers. Try to reply.
1. I didn't try open firmware reset yet. Will do it tomorrow
2. There are no capacitors on G3 B&W "Yosemite" mobo. At all. At least I didn't see anything that may look alike.
3. Sure I tried every RAM on its own and even got new bank of 256 mb RAM
4. May it be power supply? There could be leaked capacitors, I didn't take it apart yet
5. After all can it be the mobo fault?

Yes, by logic board I meant motherboard. It certainly sounds like a possibility. Power supply sounds a little unlikely if it's booting at all, but can't be ruled out yet. Anyway, please keep us informed about what you discover.