iMac G3 Rev D issues

[ddybing]

Hi!

I recently bought a Rev D (333Mhz) that has had its CPU swapped for a 266Mhz, most likely from a Rev C, although it could also be a PowerBook. The backstory is a bit uncertain.

Anyhow, I am experiencing a few issues with it. It runs great, hard drive is in good shape, image is clear. The issues I am facing seem like they are software-related, but I am not sure if they could be caused by faulty or incompatible hardware, for example in relation to the CPU swap. I understand that it might be difficult to pinpoint the exact cause of these issues, but I am grateful for any input.

The first issue I am experiencing is that I am unable to boot the original restore CDs. Rev D came with 8.6 (Rev C came with 8.5.1 and 8.6), but I am unable to boot these restore CDs. I only get a gray screen. It sounds like the CD drive is doing something, but the screen is frozen. Same issue occurs if I try to restore HD image that is on the restore CD from a live OS 9 CD.

The second issue is that I am unable to sleep in OS 9. I either get an error saying that system software for sleeping is missing, or it only shuts down the hard drive with the display still lit and with a green power button.

Third issue is that the computer is locked to 1024x768 at 60Hz with 256 colours. There is no other options, and the display is also recognized as a "VGA Display".

Also, while trying to install OS X Jaguar I encountered this weird graphics glitch.

To me some of these issues sounds like missing extensions, but I am not sure if I can just drag and drop extensions from the 8.6 CD to an OS 9 installation. And I would guess that all required extensions should be on the original restore CD so that the computer at least boots?

The machine is running the latest tray-loader firmware (3.0f2). I've put in a fresh battery, zapped PRAM multiple times, as well as run the "set-defaults" and "reset-nvram" commands in Open Firmware.

Any suggestions as to what I can try next? I can of course try to acquire a 333Mhz board to try with, but that is easier said than done as they're even more scarce than the machines themselves.
The machine is in great condition, so it would be sad to not be able to have all features working.

Thanks alot in advance!

 

[eyoungren]

The first thing I would try is locating and downloading the update for the current version you are on. Copy it over (or download it to the Mac), open, run it and reinstall it. It should pickup what's missing and reinstall everything.

Sounds to me like you have an incomplete install.

 

[ddybing]

The first thing I would try is locating and downloading the update for the current version you are on. Copy it over (or download it to the Mac), open, run it and reinstall it. It should pickup what's missing and reinstall everything.

Sounds to me like you have an incomplete install.

Thank you for your answer! Were you thinking about the firmware update or the Mac OS update?

 

[eyoungren]

Thank you for your answer! Were you thinking about the firmware update or the Mac OS update?

The Mac OS update.

 

[ddybing]

Okay, I'll try to do a fresh OS 9 install tomorrow and install all updates up to 9.2.2 and see how it goes. But I am still a bit unsure why I am unable to boot the original restore disks and 8.6 retail CDs.

 

[eyoungren]

Okay, I'll try to do a fresh OS 9 install tomorrow and install all updates up to 9.2.2 and see how it goes. But I am still a bit unsure why I am unable to boot the original restore disks and 8.6 retail CDs.

No idea right now. I'm just seeing if we can eliminate graphic glitches by reinstalling the current version of the OS. It may be that for your iMac 8.6 is too early, IDK. I don't have a lot of iMac expertise.

 

[davisdelo]

The firmware update is necessary for OS X installation, that could be the Jaguar issue. Also check that you have all of the VRAM installed, if someone went messing around in there and swapped out the cpu they may have grabbed other things too.

 

[ddybing]

The firmware update is necessary for OS X installation, that could be the Jaguar issue. Also check that you have all of the VRAM installed, if someone went messing around in there and swapped out the cpu they may have grabbed other things too.

Thanks. Yes, I've reseated the VRAM stick. There is what looks to be a 4MB stick + the 2MB on-board, so it has the standard configuration of 6MB VRAM.

I've now updated all the way to 9.2.2. Tried installing the 3.0/1.2 update again, but it already says that I am up-to-date, which Open Firmware seems to confirm.

 

[m1maverick]

The first issue I am experiencing is that I am unable to boot the original restore CDs. Rev D came with 8.6 (Rev C came with 8.5.1 and 8.6), but I am unable to boot these restore CDs. I only get a gray screen. It sounds like the CD drive is doing something, but the screen is frozen. Same issue occurs if I try to restore HD image that is on the restore CD from a live OS 9 CD.

I have almost no experience with iMacs so take this suggestion with a grain of salt. Could it be the Rev D restore disc installer is checking the hardware to ensure it's running on a Rev D iMac and it cannot proceed as it may have determined it is running on a Rev C iMac due to the 266MHz CPU?

 

[ddybing]

I have almost no experience with iMacs so take this suggestion with a grain of salt. Could it be the Rev D restore disc installer is checking the hardware to ensure it's running on a Rev D iMac and it cannot proceed as it may have determined it is running on a Rev C iMac due to the 266MHz CPU?

Thanks.

Yes, I think that this could play a part, although I am not sure either, as I do not know what information the installer/bootloader checks before starting the CD. Based on experience from e.g. SheepShaver it should boot until the Mac OS splash screen, and then tell you that this CD will not work on the current hardware.

 

[Project Alice]

I will boot up one of my Rev B’s later tonight and see what the firmware is.
Both are Bondi, running 9.2.2 and Tiger 10.4.11.

One of them has a 333MHz card, the other is a factory 233MHz.

What you’re describing sounds like a firmware or ROM issue; though it could be related to system memory, or VRAM. The ROM is located on the CPU card.

Also I would use this image for OS 9.2.

 

[ddybing]

I will boot up one of my Rev B’s later tonight and see what the firmware is.
Both are Bondi, running 9.2.2 and Tiger 10.4.11.

One of them has a 333MHz card, the other is a factory 233MHz.

What you’re describing sounds like a firmware or ROM issue; though it could be related to system memory, or VRAM. The ROM is located on the CPU card.

Also I would use this image for OS 9.2.

Thank you very much! I look forward to hearing from you.

In the meantime, I will test the universal image that you provided.

 

[Project Alice]

Thank you very much! I look forward to hearing from you.

In the meantime, I will test the universal image that you provided.

My 233MHz reports a bootrom of 1.3f2 in Tiger’s system profiler. Open Firmware reports the same version you said yours is, 3.0f2.

I could check my 333MHz one (Rev B with a Rev D card), however it requires me to press the CUDA button everytime I power it on and I don’t particularly want to tear it apart right now.
I’m unsure if the Rev D card would include a different firmware than the RevA/B card. Maybe someone else knows?
Though I would imagine my iMac wouldn’t be able to boot Tiger if it was on older firmware.

 

[ddybing]

My 233MHz reports a bootrom of 1.3f2 in Tiger’s system profiler. Open Firmware reports the same version you said yours is, 3.0f2.

I could check my 333MHz one (Rev B with a Rev D card), however it requires me to press the CUDA button everytime I power it on and I don’t particularly want to tear it apart right now.
I’m unsure if the Rev D card would include a different firmware than the RevA/B card. Maybe someone else knows?
Though I would imagine my iMac wouldn’t be able to boot Tiger if it was on older firmware.

Thanks for checking! I understand you don't want to take it apart, so no worries!

Not sure what to do now, but I think I will have to take it apart again and check the daughtercard/CPU board. I didn't inspect it when I opened the iMac last time.