Power issue

[Falcon]

Just over a week ago I decided it was time for me to bring my pc up to date a bit. I bought a second hand Samsung EVO 840 SSD, 8gb (2x4gb) mushkin ram, am EVGA NEX750B power supply and a new R9 270x graphics card.

Last weekend when I went to install all the above equipment I had issues getting the my pc to power up, the case fans, graphics card and cpu fan would all power up for about a second then power down for a couple of seconds and then repeat over and over again. Thinking it might be a psu issue I went a bout a Corsair HX650 and the same problem occurs. However if I use my old Corsair VX450 I can get my pc to work boot etc. I've done the paperclip test on both the psu's and they seem to work fine.

Any suggestions what might be causing this power problem? Ideally I'd like to use one of the newer psu's.

Thanks

 

[Falcon]

That does seem weird that an older and weaker PSU works better than a newer unit.

I can only imagine the motherboard is somehow sensitive to which PSU it likes.

What board is it?

The board is an Asus p7p55d-e lx

 

[Falcon]

Seems a bit strange that it affects 2 different makes of psu's

 

[Falcon]

Out of the 2 newer psu's which one do you think I should keep? The corsair is new but the EVGA is slightly more powewrful.

 

[Falcon]

EVGA supernova NEX750B1

Corsair HX650 (model number 75-001217)

 

[Falcon]

Excellent, thanks for your help.

Now to work out what board and cpu to get. Would a MSI Z87M gaming be a good choice?

 

[Falcon]

Budgets tight and I've seen the MSI cheap on a well known auction site