Why does my IMac Always Spontaneously shut down?

[Keekarama19]

Can anyone help me please?
I have an imac G5 running 10.4.11 and it automatically shuts down after an approximate idle hour. I haven't timed it, but it's close to an hour, a little less maybe.

Is the internal battery dying? Can anyone help me figure out this annoying problem so I don't have to spend a fortune on a shop repair?

Thank you in advance for any advice any of you amazingly smart people might have.

 

[simsaladimbamba]

Does it really shut down or just log you out or goes to sleep?
Have you opened Applications / Utilities / Console yet to see, what is happening?

 

[Raid]

^ To simsaladimbamba's point if it's just going to sleep after an hour it might be your Energy Saver preferences. If it completely shuts down it could be a number of things that the console could help figure out.

 

[VulchR]

If it is not just sleeping, then that is not good. Does it ever shutdown unexpectedly while you are using it? If so, it might be some component is overheating or failing (ouch).

 

[GGJstudios]

Try resetting the SMC.