Boots and it turns off

[deadzone]

Well, i had some problem with my XP since i scraped to much of the gaps, yesterday i took it out so i can put some AS3 hi was running ok ( its and XP1800 running at XP1900 and sometimes at XP200, i dont know way and all of this is in AUTO ) when i put it back the computer start but it turns off in a few seconds. Also i installed a new 12cm YS fan to may Rad. In total i have 4 8cm and 1 12cm, could this be a power problem? I tried disconecting the fans but it wouldnt keep on. My PSU is 400.

Thanks