iMac G4 running hot

after an interval of time that seems to be getting shorter, the computer will overheat and shut itself down.
Kevin Michael Vail wrote on :

My mother is visiting me for a few weeks, and I have set her up to use my old iMac G4 while she's here. All she's doing is email and a couple of games (Snood, mostly, some Bejeweled 2), but after an interval of time that seems to be getting shorter, the computer will overheat and shut itself down. Sometimes it has to be unplugged and plugged in again before it will restart (even after allowing time for it to cool down).
This can't be good!

iMac G4, 768meg, running Leopard (10.5.5, I think). I'm not even sure what to start looking at to figure out what's wrong, so any suggestions will be gratefully accepted, either via email or here in the group.
It's not a serious problem but it's frustrating for her.

Thanks in advance for any suggestions!

Jolly Roger replied on :

In article kevin-024088.18382030122008@redacted.invalid, Kevin Michael Vail kevin@redacted.invalid wrote:

My mother is visiting me for a few weeks, and I have set her up to use my old iMac G4 while she's here. All she's doing is email and a couple of games (Snood, mostly, some Bejeweled 2), but after an interval of time that seems to be getting shorter, the computer will overheat and shut itself down. Sometimes it has to be unplugged and plugged in again before it will restart (even after allowing time for it to cool down).
This can't be good!

iMac G4, 768meg, running Leopard (10.5.5, I think). I'm not even sure what to start looking at to figure out what's wrong, so any suggestions will be gratefully accepted, either via email or here in the group.
It's not a serious problem but it's frustrating for her.

Thanks in advance for any suggestions!

It would help to know which specific model you're talking about. To find out, run /Applications/Utilities/System Profiler and copy the Serial Number to the clipboard. Then head over to http://support.apple.com/specs and paste the serial number into the Search Tech Specs field.

Also, when it overheats, you say it will "shut itself down"; but how does it behave specifically (what happens first, next, etc.)?

Kevin Michael Vail replied on :

In article jollyroger-D6FCE9.18440230122008@redacted.invalid, Jolly Roger jollyroger@redacted.invalid wrote:

In article kevin-024088.18382030122008@redacted.invalid, Kevin Michael Vail kevin@redacted.invalid wrote:

My mother is visiting me for a few weeks, and I have set her up to use my old iMac G4 while she's here. All she's doing is email and a couple of games (Snood, mostly, some Bejeweled 2), but after an interval of time that seems to be getting shorter, the computer will overheat and shut itself down. [...]

It would help to know which specific model you're talking about. To find out, run /Applications/Utilities/System Profiler and copy the Serial Number to the clipboard. Then head over to http://support.apple.com/specs and paste the serial number into the Search Tech Specs field.

It's the iMac (USB 2.0), 20-inch display...the "desk lamp" model. The only thing plugged into the USB is a Bluetooth dongle, through which the older Apple wireless keyboard and a Kensington mouse are connected.

Also, when it overheats, you say it will "shut itself down"; but how does it behave specifically (what happens first, next, etc.)?

I haven't actually seen it happen, but it apparently just shuts down suddenly...screen goes black and power is off. I think from what she's said that the fan starts running really quickly first.

Jolly Roger replied on :

In article kevin-BD4A5B.21392830122008@redacted.invalid, Kevin Michael Vail kevin@redacted.invalid wrote:

In article jollyroger-D6FCE9.18440230122008@redacted.invalid, Jolly Roger jollyroger@redacted.invalid wrote:

In article kevin-024088.18382030122008@redacted.invalid, Kevin Michael Vail kevin@redacted.invalid wrote:

My mother is visiting me for a few weeks, and I have set her up to use my old iMac G4 while she's here. All she's doing is email and a couple of games (Snood, mostly, some Bejeweled 2), but after an interval of time that seems to be getting shorter, the computer will overheat and shut itself down. [...]

It would help to know which specific model you're talking about. To find out, run /Applications/Utilities/System Profiler and copy the Serial Number to the clipboard. Then head over to http://support.apple.com/specs and paste the serial number into the Search Tech Specs field.

It's the iMac (USB 2.0), 20-inch display...the "desk lamp" model. The only thing plugged into the USB is a Bluetooth dongle, through which the older Apple wireless keyboard and a Kensington mouse are connected.

Also, when it overheats, you say it will "shut itself down"; but how does it behave specifically (what happens first, next, etc.)?

I haven't actually seen it happen, but it apparently just shuts down suddenly...screen goes black and power is off. I think from what she's said that the fan starts running really quickly first.

Ok. The first thing I would do is install a temperature monitoring program such as Temperature Monitor, and begin monitoring the internal temperature of the system to see if these spontaneous shutdowns actually do coincide with temperature extremes. You can get Temperature Monitor here:

http://www.macupdate.com/info.php/id/12381/temperature-monitor

It's not immediately evident, but Temperature Monitor actually tracks and graphs the temperature of system components through time, because the "history" window is hidden by default. If you show that window after starting it up, you'll see the graph.

For quickly viewing current temperature values at a glance, iStat Menus is excellent as well:

http://www.macupdate.com/info.php/id/25230/istat-menus

The other thing I would do right off the bat is examine the system and console logs immediate after each spontaneous shutdown, and make note of any error messages posted to either log regarding the power manager (look for lines that mention "ApplePMU" or "PMU"), as such messages might help determine exactly what's causing the shutdown.

Feel free to post whatever information you glean here for further diagnosis.