G3 iMac shuts down randomly

[notcrazy_iminsane]

This is a recent problem in my sister's iMac. She claims that it will shut down without warning at random times. I've done some research and most sites say it's the PAV board, but it would get progressively worse if it was the PAV board wouldn't it? I mean, some times this thing can run for hours with no problem or only five minutes then shutting off.

The main part of this that concerns me is the other day when my sister said it shut off randomly with "the sound of glass hitting something inside the computer". It still runs and shuts off randomly, I just want to know where to start on fixing this problem :-/

 

[phreakout]

It could possibly be the PAV board, but that glass breaking sound usually would indicate to me that the RAM could be faulty as well. Does that sound happen when the power button is pressed? If so, then you might want to try a new set of RAM.

When a PAV board goes bad, typically the first thing you'll notice is a zapping sound and also the light around the front power button will go amber. In some cases, when you press the power button, it will seem as though the iMac is not getting enough power to even run. So it will immediately shut down and reset itself to the start position.

Which iMac G3 is this model? Does it have a tray-loading CD-ROM or is it a slot-loading type?

73s de Phreakout. :rambo:

 

[notcrazy_iminsane]

It's a tray-loading iMac.

I haven't experienced the glass sound myself. My sister claims it only happened once :-/ I've only seen it shut off twice myself. Once after starting it up it shut off right after it showed the happy mac. The second time was when she turned it on and it shut off in the middle of booting the OS. It's just odd whenever it decides to have fits. After those two, it booted normally and ran for a couple hours before we turned it off.

 

[racepres]

Time for Ram check!

RP

 

[phreakout]

Yep. Time to pull out a copy of Tech Tool Pro v.4, Norton Utilities v.3.5 or the Hardware Test disk that came with the iMac, if you have them. If not, PM me and I'll see if I can burn you a copy.

If it turns out to be also the PAV board, it kinda doesn't surprise me that much. That Mac is going on 13 years old and with how many times it's been powered up, restart and shutdown can put some stress on the HV components. You might be able to look here or on eBay for a matching replacement board. I'll look around and see if I have the service manual for tear-apart diagrams and diagnostics.

73s de Phreakout. :rambo:

 

[notcrazy_iminsane]

All I got with the iMac was the computer, keyboard, and mouse :-/ I got it from a recycler, so no disks. I'll poke around on the internet and try and find some downloads of the software I need. If I can't find the right stuff I'll let you know if I'll need that burned copy.

 

[phreakout]

What version of Mac OS is it running? Just curious.

In a pinch, try removing the PRAM battery. Also, try removing 1 stick of RAM at a time until stable.

Just a note: In order for Tech Tool Pro to boot on your iMac, you'll need to verify if the iMac has the right firmware update applied; I think it's version 4.1.8f4, or something like that. In the mean time, I'll see if I can get cracking on a bootable copy of TTP 4 for you.

73s de Phreakout. :rambo:

 

[notcrazy_iminsane]

If I remember correctly it's running 8.5. Not quite sure on the firmware though :-/

 

[phreakout]

In the Apple menu, there's the Apple System Profiler. Click on that and just below the listing for the processor somewhere should be the version number of the ROM(s). Just post all that.

73s de Phreakout. :rambo:

 

[notcrazy_iminsane]

I just now got around to working on that iMac again.

OS 8.6

ROM version $7DD.44B5

Boot ROM version 3.0.f3

 

[phreakout]

Okay. Now with the iMac running (that is, when it's cooperating with you that day), go into the Apple Menu (Top left corner of the screen) go into Control Panels, then select Software Update. Make sure you have the correct settings for Internet Access chosen as well before you use Software Update. In other words, if you are using Ethernet as your connection (i.e., cable modem or ADSL, etc.) make sure you change the settings in the TCP/IP Control Panel for Elthernet and "Using DHCP Server", so that it automatically will establish the IP address from your router. If you use dial-up modem, make sure you dial into your ISP and establish a connection that way. Of course, if you obviously already know all about this, then I'll take your word for it that you have successfully connected online and that I am just being condescending towards you. )

Anyway, use Software Update to download as much updates for your iMac. Hopefully, one of them will be iMac Firmware Update version 4.x.x or equivalent. Follow the instructions and get the firmware updated. The whole purpose of this is to be ready just in case you need Tech Tool Pro 4.x, which I'm working on building a CD of.

73s de Phreakout. :rambo:

 

[notcrazy_iminsane]

Is it possible to get these updates without taking the iMac online? We have only have two phone cables in the house, one for the phone and the other for my dad's computer to have dial up :-/ If all else fails, I can take the iMac to school and use their internet.

 

[notcrazy_iminsane]

Stupid question on my part. I just did a search on the Apple website and found the firmware update. It says the firmware 4.x.x is for the slot-loading iMacs. 1.2 is for the tray-loading iMacs... I downloaded both to be safe.

 

[phreakout]

Let me check and see if the Mac OS 8.6, 9.1 and 9.2.1 install CDs I have contain other software updates you'll need and we'll talk further.

73s de Phreakout. :rambo:

 

[notcrazy_iminsane]

Sounds good to me

 

[phreakout]

Okay, I looked around and my OS 9.1 Install CD is the only one that has a firmware update for your tray-loading iMac G3. It is firmware update version 1.2, release date May 19, 1999. It is about 1MB in size. I can send it to you via email or you can get it from Apple's web site, under the support category. If you do the latter, you'll have to hunt around for it.

73s de Phreakout. :rambo:

 

[notcrazy_iminsane]

I believe I downloaded that firmware update. Let me check my jumpdrive to make sure I snagged it. If I did get it, how would I go about installing it? :-/

 

[phreakout]

There should be a README file on what to do included with the download. If not, I can email the whole thing to you.

73s de Phreakout. :rambo: