Computer turns on and off

[luigi_90]

Hi, I recently assembled a new PC. when I turn it on, all fans and lights turn on... for one second, after that all components turn off, 3 seconds later it turns on again and so on repeatedly.
it doesn't even POST.
First thing I did was to test the system with other (VERY old) power supply everything worked fine, no problem.
so I thought the new PSU was damaged, for my surprise, when I put it in other (VERY old) computer... it work!!
I have build a lot of systems and it's the first time I see this
How is it possible?
Is there a problem with the psu?

foxconn p55a s
antec truepower 550w
core i5 750
4GB g.skill ripjaws
nvidia geforce 8500gt

 

[masterasia]

You might have solved your own problem. Get a new PSU.

 

[luigi_90]

It's a shame but yes, I'll buy a new one.
I just want to be sure it's not the motherboard...

 

[luigi_90]

if it is any help, there is someone with the exact same problem
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006&Tpk=corsair%20750
it's a one-egg review, it has a video and everything
he says its something related with the voltages on the PSU, and I hope so...

 

[ktkcad]

if it is any help, there is someone with the exact same problem
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006&Tpk=corsair%20750
it's a one-egg review, it has a video and everything
he says its something related with the voltages on the PSU, and I hope so...

I have the same problem. Did a new PSU solve it for you? Thanks

 

[luigi_90]

I have the same problem. Did a new PSU solve it for you? Thanks

well yes, I got a corsair CMPSU-650TX, and it's working fine
but I don't know what was the problem, the Antec PSU is working PERFECT in my old computer.
As I said before this is the first time I see this, I don't know if it's a compatibility issue, or something else

so yes, new PSU fixed the problem!