View Full Version : Beige G3 Crashes all the time!

06-25-2001, 04:53 PM
I have a G3 266 overclocked to 300Mhz which is all apple did right? Anyway I have been running it at that speed for neary 2 years. Anyway I recently purchased a 40gb seagate barracuda III installed it and from then on my machine seemed to hang. Especially whilst running serious games! hence the reason I suspect it's overheating. The processor used to run @ 66 degrees celsius! I assume that is ok however now it's @ 77 Also I noticed my upgrade on other machines ran alot lower e.g 45 and 17. is my chip getting too hot? or what? ~The main fan inside is still going so no probs there.If it's hot what can I do! please help!

06-25-2001, 05:38 PM
I have a G3 266 overclocked to 300Mhz which is all apple did right? I'm not exactly sure what you are saying here. Apple does not overclock CPUs, boards or chips. I'm fairly sure they have NEVER done this, but its hard to prove and I dont follow things that closely. Apple has done some STUPID things, but they arent that stupid. http://macgurus.com/infopop/emoticons/icon_smile.gif

The Max temp C for a PPC/G3 that I know if is 65C. So your overclock was orignially to hot. Now NewerTECH made a PB1400 upgrade that was 'rated' to run at 105C and often ran at 100C (boiling! http://www.macgurus.com/ubb/eek.gif ). I'm sure this had nothing to do with overclocking and everything to do with the fact the CPU & large cache was stuffed in an old PB case. CPU's do wear down over time - and normally a vendor will DOWNCLOCK a cpu. Since they ship thousands and millions of these they have to have a very HIGH RELIABLITY, since a 'small' return of 1% on a MILLION chips would be 100,000! http://macgurus.com/infopop/emoticons/icon_redface.gif

My G3 was running at 54C for awhile, then I discovered that the thermal donut (gromet) was preventing the heatsink from making good contact with the chip. The big tip off was that the heatsink was cool when the CPU was hot. Of course the whole point of the heatsink, as we all know, is got get HOT so the CPU does not burn up. Now its running at 36 to 44C, average under regular work is probably 40C. Its a REV3 G3/466 from XLR8 running at 500/250/50.

1) Clock your chip down to its rated speed.
2) Cool it down to about 50C max - PPC chips normally run fairly cool. While the software can often be wrong, its usually accurate in showing temp differences. An 11C increase in temp is BAD! http://www.macgurus.com/ubb/crossbones.gif
3) If you have a REV A, you may need to get a PCI IDE/ATA card. This will give you more speed anyway and it can handle up to 4 drives (not sure about the powersupply though).
4) Even if its a REV A you should not have any issues - so long as it is the only IDE/ATA drive on the channel. All G3 Macs have two IDE/ATA channels, but the early models (Gossamer/beige & Yosemite/Blue) Macs do not support slave drives in REV1/REVA models. I think some people have forced the issue, but I do not know of any success. You are only flirting with disaster if you run master/slave on a REVA.

45C is about right. Of course 17C is way low, unless its REALLY cold where you are. http://macgurus.com/infopop/emoticons/icon_smile.gif

If you are running with the G3MT, you might be able to use one of those Burly TEMP bezels. This can give you a good idea of the case temp. You should also try running the system with the case open. Make sure you are grounded and then touch the G3 heatsink. If its VERY hot or barely warm YOU HAVE ISSUES.

I think the slowest G3 may be 366 - you could probably get this for under $200US - not sure about VAT, other taxes, markup or death.

Life in the fast lane leads to:
The Resteraunt At The End Of The Universe.

06-25-2001, 05:47 PM
Oh btw it also had a voodoo 3 in it. but I took it out to see if it was the problem. but no such luck. oh b*ll*x now where did I put that jumper?

06-25-2001, 05:54 PM
Ok so do you think it's the heat from the hard drive? I never had this problem (well as often) before. so I can't cool it down with ice? or perhaps a better option would be a better fan/larger heatsink. it's a dT case btw

06-25-2001, 06:09 PM
Ok I think I'm gonna clock her down! sat here online with the case open and it's fluctuating between 87 and 91! so I think I'll have to find a makeshift jumper
will get back

OWC Larry
06-25-2001, 08:19 PM
Make sure the clip is correct on the heatsink. reversing the clip is very easy to do and reduces the heat transfer SIGNIFICANTLY.

The heat sensors in the G3s are not the most accurate, but those number still seem high.

Apple did not overclock 266MHz processors for their G3/300s... they used 300MHz speced parts. Without a doubt, kill the overclock and see where it goes from there. For under $70 you can get a real 333MHz with 1024K cache. The cache makes a big difference.

06-25-2001, 09:32 PM
Cheers Guys. I just made a minor modification of adding a 240volt fan just behind the zip/cdrom drive works a treat. I'm now running @ a relatively cool 63 degrees and 59 whilst idle. no crashes as yet! will consider getting a better fan to fit the power supply. I Got the idea from here. http://www.xlr8yourmac.com/G3-ZONE/cooling/index.html They reckon you can even squeeze 315Mhz outta this ageing chip! Thanks anyway

06-26-2001, 04:12 PM
Hi again.

Repositioned the fan to where the speaker was, made it defunct since I have a 1710AV anyway. Angled it toward the processor and now it's idling @ 49 degrees! and working @ 55. I am determined to keep 301mhz until I have to upgrade! next to put the voodoo back in!

06-26-2001, 06:04 PM
That still seems a bit hot. Did you check the heatsink?
When running is the heatsink warm, hot or what?

Did you say the CPU got up to 91C when the case cover was off? http://macgurus.com/infopop/emoticons/icon_redface.gif Maybe your temp is way off??? I would double check to make sure heatsink is in good contact with the CPU.

If its stable, I guess you are OK.

So you are hooking the fan up to the 240V AC power?
You should be able to get a fan to run off the internal 12V power (like a HD connector). You could also try putting an fan in a free PCI slot - if you have one left.

Life in the fast lane leads to:
The Resteraunt At The End Of The Universe.