New Computer Problems

[Slam799]

My friend an I built a new computer out of brand new parts that we bought. After we got it put together we plugged everything in and turned it on. The computer turned on spans started spinning lights came on, but no signal was sent to the monitor. I figured that this had something to do with the graphics card. So my first thought was that it was because the power supply was considerably underpowered for this computer. So we tried getting a second power supply and using it for the Graphics card only, and using the first power supply to power everything else. this time everything turned on, including the fan on the graphics card. Still no signal to the monitor however.

So then we tried swapping out the old monitor that we were using for a newer one, we were told that it might be the problem. that however didn't make a difference.

And this is where it gets really annoying for us, after sitting and contemplating what to try next, we decided to try and power it up one more time. This time we hit the power button and NOTHING happened. no power, no lights, no fans, not anything.

I have since tried the power supply in another computer and it worked fine. So what else could have caused this lack of power, and how can I test to try and fix it.

[Crafty]

Well without knowing the full specs of this computer, it's anyone's guess what the problem could be. I would suggest, you add a list, of all the things you placed in this computer.

[Slam799]

4 gigs ddr2 800 ram, intel q6600 2.4 ghz quad core processor, bfg nvidia 9800 gtx 512 mb, 160 gig sata hard drive i was so excited to get this computer but now that it wont start im totally crushed, i was talking to one of my friends and he was saying my psu needed like 25 amps on the +12 volt rail and my psu only has 21 is that a posssible cause of it not working?

[Crafty]

What psu have you got - Make, watts, etc...

[Slam799]

its a 450 watt power supply i probably should have guessed it wouldnt be good enough because it also came in a combo with the tower i bought, sorry i dont know much else than the wattage

[Crafty]

The 9800 requires 25 amps combined on the 12 volt rail.

You will need a decent psu to run that computer.

[Slam799]

so if i were to buy a, something around, 800 watt power supply would that start everything up agian?

[Slam799]

and suppose i wanted to sli does that mean i would need 48 amp on the 12 volt rail or still just 24?

[Crafty]

Yes it should do, However, I was just abit concerned when you said that you get nothing now. You could try taken the card out and seeing if your computer atleast starts up again. I know you won't see anything on the screen but atleast you will know it starts.

[Slam799]

If it does start does that imply that the graphics card is bad, or that the power supply knows its limits and just wont even try anymore

[Crafty]

For 2 cards power supply then needs to have (in total) at least 45 Amps available on the 12 volts rails.

For 1 card i would get 25 - 30 amp on a 12 volt rail, to be on the safe side.

Yes it could be that the psu not powering the computer up.

[Slam799]

oh and my mother board (p5n-e sli) doesnt have onboard graphics and no monitor slot on it, but should i still try just to see if it will start?

[Crafty]

I would yes, I have never come across anyone using another psu to run a graphics card and am just wondering if this has caused damage.

[Slam799]

well we have tried other graphics cards also, we tried a geforce 8500gt and a radeon x1600 pro and neither of them were able to send any kind of signal to the monitor

if it has caused damage, do you think it would have caused damage to other componants or just the graphics card

also its doesnt just give us nothing, the light on the fan flashes like its trying to turn on but then instantly shuts off again

[Crafty]

Is this the heatsink fan you are talking about, if so - Have you double checked that you have correctly seated the heatsink/fan and applied the right amount of thermal paste to the cpu!!