Computer won't boot

[hockeypunk]

The other day my brother was playing a game on my computer and it started to make this clicking sound for a second and then crashed. After that it wouldn't boot at all, but i narrowed it down to that my power supply and video card were both fried I replaced both of them and now when i boot the computer up it only stays on from anywhere to 20 seconds to 3 minutes and then just restarts and does the same exact thing. I also tried replacing the ram this mornin, but it still does the same thing. Most of the time it gets past the bios boot screen and sometimes it gets as far as loading up Windows.

MB Asus p4p800 se
CPU Pentium 4 2.8 Ghz
RAM 2x Kingston 512mb ddr 400
2x Vdata 512mb ddr 333
HD Western Digital 250g Sata2
OD Samsung Litescribe Dvd/rw
VC 256mb Geforce 6200

 

[damientbayless]

How many watts is the psu? and your positive you have all the power connectors in place on the mobo?

 

[blacklabelrum]

could be a heat problem? ckeck all your fans etc.

 

[hockeypunk]

my psu is 550w and yes there all in the right place and i checked my fans but they seem to be working fine.