i just a bought a radeon 2600 graphics card and online it said it only need 175 PSU so i thought my powersupply of 295 watts would be good,and at first it worked well and when i used the computer for log time and restarted it it told me that on a black screen that i needed to have my power connected so i do not know what this means but i think i need a bigger powersupply and i got one that is 400 watts buts its too big for my computer so can i put the powersupply outside the computer,plug in everything and use it???or is this problem even the power supply.I just get this black screen right after i turn on my computer and in red flashing writing it tells me that my card needs to be connected. but then othe times it works....????,i donts know when it will work and when it will not.Some one please help me