need help troubleshooting new computer build

Hey guys,

You were all so helpful to me in researching the parts I wanted for my new computer build. Anyways, they all came, with some help I threw it all together, but now it doesn't work lol. Computer powers on fine - the PSU is obviously working and powered on right as all the fans turn on, the power LED on the mobo turns on, the video card fan turns on, etc. But there is no video signal at all. So obviously something is fairly wrong. I tried plugging the monitor into both the video card and into the mobo. Neither worked.

What can I do to figure out what the problem is? At this point, I assume it is any of: 1) the motherboard, 2) the RAM, 3) the CPU, 4) I RED ENGINE GORED ENGINE GORED ENGINE GORED ENGINE GOed up and plugged a cable the wrong place somewhere.

Thanks!

Here are the system specs:

Mobo: Asus m4a78t-e
CPU: AMD Phenom II x4 955 3.2ghz
Memory: CORSAIR XMS3 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600
PSU: OCZ ModXStream Pro OCZ600MXSP 600W ATX12V V2.2 / EPS12V
GPU: XFX HD-487A-ZHFC Radeon HD 4870 1GB 256-bit GDDR5

Well, of course, there's all the usual things. Make sure all the proper cables are plugged into the proper spots, and make sure the video card is properly seated.

Next thing to do is to remove the video card from the computer and see if it boots using the on-board video. If it does, you may need to get into the BIOS to disable the on-board video before re-installing the video card. Make sure that the video card is fully seated in it's slot and make sure you have the proper power connector connected on the video card - the HD4870 requires 2 6-pin connectors iirc.

Another approach would be to disconnect everything and then reconnect them one at a time. For example, disconnect everything from the motherboard except the cpu, power supply and RAM and see if that starts up (using the on-board video). Then connect the drives and try again. Keep plugging things back in until it stops working and there's your culprit.

So, you cannot boot into the BIOS?

Either your case or motherboard should have come with a little speaker - if you have that plugged into the mobo (consult your mobo manual to see where) it will emit a "code" of beeps that can help to tell what is wrong when your system will not boot up.

Do you have the HDD connected with both a SATA power cable (to the PSU) & a regular SATA cable (to the mobo)?

Do you have the video card inserted and seated securely into the topmost PCIe x 16 slot? Do you have both of the PCIE 6 pin connectors from the PSU plugged into it?

Those are the things that come to mind first off. Check and make sure that everything is indeed plugged in and seated well.... one slightly loose connector could be all it takes.

*oops - Quaker beat me to the post... oh well - double coverage never hurts hehe...*

FYI - from in-game: He doesn't have a speaker, but clearing the CMOS seems to have worked.

excellent!!! - thanks Quaker

why do you have 3 sticks of DDR3 RAM? phenom II CPUs are dual channel, so you only need 2 sticks.