computer shuts off during power up

[robml22]

I have a computer in our office. I really don't know what kind it is. It say "Lti" on the front of it, but anyways it was turned off last night for the first time in a long time and this mourning when I powered it on it started to turn on, made one beep and then shut off. I flipped the power switch in the back and tried it again same thing it just looses all power after it makes on beep. I thought it might be the power supply so I hooked up that power supply in another computer and and it worked fine. If anyone has any ideas I would appriciate it.

thanks

[Flame]

Is overheating a possibility?

Flame

[robml22]

This computer is not being over clocked. The fans seem to turn on for those few seconds that its on.  It could be a possibility.  I'm wondering if this could be a sign of a bad mother board.  I don't know enough about motherboards to know if it could be this or not. The only thing I know for sure is that its not the power supply.

[GX1_Man]

What if you remove and reseat the RAM and all cards in the machine? If no joy, the next thing I would do is disconnect all the drives and and remove all of the cards except the video and see if it will boot. If it does, add one thing at a time until the culprit is found. If not I would test the RAM (www.memtest86.com) if possible in another machine. If that cannot be done, then the suspects are motherboard, CPU or RAM (going on your assertion that the PSU is good.

Perhaps a local shop could test the CPU. If OK, that would be the motherboard as the most likely suspect. Do you happen to know the processor type and speed? Do all of the fans, especially the CPU fan come on, at least initially, or is there enough time to see?

[robml22]

Thanks for the advice I'll give those a try.  Both the CPU fan and the PSU fan come on for about 2-3 seconds before everything shuts off and it appears that there is no power, but if I flip the switch on the PSU I can get it to come on for a couple more seconds.  I'm not sure about the processor I'll have to get back to you on that, its not infront of me right now. Thanks again for the advice.