iMac (g4 700mhz) freezes up

[quote]Originally posted by fishboi:
<strong>Ok guys/gals.... here is the deal. I bought my wife an iMac back in Feb. and we can't figure out why it'll freeze up when we play games. So far it has completely frozen up with the following games:
Starcraft
Galactic Empires
Alice,
and now today, Warcraft 3!!!

all of these are played in 10.1.5, and we've got 384 megs ram.

This is the ONLY time that the computer ever hangs up, and it has become completely annoying. Does anybody have an idea on what I can do to fix this problem? I am thinking that I'm gonna do a new system install, but that is gonna be a BIG undertaking.... she has got a LOT of stuff on here, pluus we have four different user accounts going.......

anybody?
:confused:

todd</strong><hr></blockquote>

Can you elaborate on "freeze up?" Does it literally freeze in OS 9/Winblows fashion (mouse, keyboard stop working, all processes stop)? Or does it kernel panic? Does it just spin endlessly?

Sounds like it could be related to the GPU since its happening only on games that run fullscreen as such, and no other time.

I would try the usual stuff:

--Run "update_prebinding" in terminal. As I always say, this SHOULDN'T fix anything, but it sometimes does (go figure)

--Reboot the machine and zap the PRAM as you do so
(As soon as you turn it on, hold down Command-Option-P-R (thats 4 keys) until you hear the chime--that's once....I'd hold it down and zap the PRAM 4 times (4 chimes) to be safe)

--If this doesn't fix anything, reset the Open Firmware:

Boot the machine into Open Firmware by holding down Command-Option-O-F (again 4 keys) as soon as it turns on. When you see the Open Firmware prompt, let go. Type the following:

reset-nvram (hit return, it should say ok)

Then type

set-defaults (again, hit return, should ok)

Then finally type

reset-all (hit return)

And the machine should restart. Do not make any typos in these commands. They are very important.


FINALLY if this does not work, find your Apple Hardware Test CD (in iMac CD bundle) and boot off this and run the full test to make sure there are no hardware issues. Beyond this and knowing nothing about its "freeze" (see first thing I said) this is all I recommend short of a format-and-reinstall.

Does the freeze tend to happen after about the same time or is it totally random? That is, does it sometimes freeze 10 seconds into the game or is it always 15 or 20 minutes into the game?

I'm thinking this could be a heat problem. Games exercise the whole computer a lot more than standard programs so there is more heat to get rid of. My kids used to leave a blanket over the top of their blueberry iMac. After about 30 minutes it would freeze up. I also have a powerbook with a poorly attached heat sink (long story, pilot error). I use thermoindock to monitor the temperature. I can see that most things only raise the temperature a little but playing QT movies stresses the CPU a lot and raises the temperature till it finally siezes up. I don't think you can use Thermindock on the iMac as the newer G4 chips don't have a temperature sensor.

Check that you don't have the vents blocked (top and bottom). Check that the fan turns on and speeds up as the machine is used. There is also a remote chance that the heat sink came loose in shipping. If nothing else fixes this then call Apple support. You should still be under warranty. You also might try raising the iMac slightly to give it more clearance underneath.

[quote]Originally posted by fishboi:
<strong>Well, no luck....... I did everything you guys mentioned, and ran the Apple Hardware Test CD. It didn't find any problems. My son had been playing Warcraft 3 all evening w/o a hitch, so I figured I'd give it a try...... and the !@#! locked up on me! I am going to try a different mouse just for the hell of it, and I guess do a system reinstall this weekend....groan <img src="graemlins/oyvey.gif" border="0" alt="[No]" /> </strong><hr></blockquote>

It's possible that you have some bad/cheap memory, since it seems to happen most often when playing games. Try removing the additional RAM and see if your problems persist.

just off the top of my head, i know that there is a firmware update for some specific iMacs. have you also run all of the software updates available. at one point there was a release of new nVidia drivers, not sure if you've got those yet or not, but probably considering your OS version.

these are all running in straight OSX mode, or are you playing them in classic within OSX? (i have WC3 but play on my PC instead of my iBook, although it's installed on both.) i assume these are all in straight OSX mode.

next time it locks up totally, try unplugging all of the USB devices and plugging them back in. this includes any USB hubs you might have. I've seen those do some really weird things.