Computer Problems!!! HELP!

[pandapanda]

Im having a problem with my computer where it will blink for one second and then shut off. When i switch the power supply plug from the 8 pin slot in my graphics card (ati radeon hd 4850 x2) to the 6 pin slot, the mobo powers up except it does not post. In addition, after i swap the power supply plug, i get a long beep followed by 2 short beeps (when i tried taking out the ram to see if it was the mobo, it beeped indicating the motherboard is not the problem)

ive been trying to fix this computer for almost a year and after many RMAs and reconfiguring i am stumped
any help would be appreciated

MSI x58 platinum
Mushkin DDR3 ram (6 gigs)
ATI Radeon HD 4850 x2
Intel core i7 920
Corsair 750W power supply

 

[badge]

Sounds like the video card is not getting the proper power needed. Or it's dead. Try a different video card.

 

[pandapanda]

i already tried another video card =( it was my neighbors and we made SURE that it worked (it worked in his computer) when we switched it, my computer did the same thing...update however... i was messing around with my comp in the last couple of minutes and i noticed that one of the video card fans (it has two) spins abnormally fast (like a shredder fast) and the other one doesnt spin at all

(this is only when its plugged in to the 6 pin connector...when it is plugged into the 8 pin it still just blinks and then dies)

 

[saint19]

Hi newcomer and welcome to the Tom's hardware forum.

Check your mobo that don't have any short with the case or another component of the rig.

 

[pandapanda]

i doubt it does because the motherboard is turning on and beeping properly..all of the LEDs are lit up according to the manual (which means its functioning)

 

[obsolete99]

As badge said, it doesn't sound like it's getting enough power. I don't have first hand experience with that card, so someone correct me if I'm wrong, but doesn't that card need both the 6-pin AND 8-pin plugged into it? Unless I've misread, have you made sure that both are plugged in at the same time?

 

[pandapanda]

ive tried that...the same thing happens: it just blinks and shuts off. when i first built the system i believe i only had the 8 pin plugged in, and it was working just fine

 

[obsolete99]

Your power supply, is it the TX or HX? Did you test it to see that it is working properly, maybe tried a PSU from a different computer? Have you assembled all components outside the case just to be sure it's not shorting somwhere, beeps and lights don't always tell you everything. Are you sure that you used to run the card on only one power connector? I've never heard of that successfully and thought doing so might actually damage the video card. You said that your neighbor's video card didn't work in your computer, either; did you try putting yours into theirs?