what can cause pc to power up for a second, then power itself off?

[ny_driver]

it was doing it yesterday when I first got it, but then that ceased to happen. I finally got it programmed with OS and stuff, then today I had a bad flash, took it all apart, then decided to try to recover the bios before getting a new chip, put it back together, and now it's doing this again. It's only powering up by the switch on the PSU also, which it was also doing yesterday at first.

Another day, another problem.........

 

[lopri]

Hello and welcome to AnandTech Forums.

What motherboard, CPU, and PSU do you have?

 

[lenjack]

HSF not connected to proper header?

 

[ekoostik]

Could be almost anything. Bad HSF connection. Bad RAM. Incorrect voltages or settings on RAM. Shorting on the motherboard or any component. Plugged in USB device. Etc, etc. As requested, please list motherboard, CPU, PSU. Also include RAM (how much, model, voltage), GPU, HD (RAID/IDE/AHCI/SATA), any 'extra' PCI cards, any USB devices plugged in, etc. Did you make any changes to the BIOS? Did you make any software based changes (such as software OC). Tell us anything else about this build, is it new, did a component just change, etc.

 

[her209]

I dunno, but my Dell Optiplexes do a quick start and shutdown when power is applied to the power supply or the LAN connection becomes active (to listen for WOL packets).

 

[MonstroMart]

Can be a compatibility problem between PSU and MB. Or something else hard to know.

Same thing happened to me when i bough an Enermax Liberty PSU. Everything worked fine for 6 months or so. Then all of a sudden the computer refused to boot. I searched on the web and found that my PSU had problems working with my MB (DFI Lanparty). I bouth a new PSU and my computer did boot again. I gave my Enermax Liberty to a friend and it worked like a charm for him. In fact he still has the PSU.

 

[ny_driver]

I switched PSU and it runs fine. I took the other (possibly faulty) PSU and put it in a different system and it has worked perfectly. Stranger things have happened I suppose. sounds kinda like your deal MonstroMart.

The system is listed in my signature, although I could add the PSU to that.:hmm: