Built a new PC, nothing shows on monitor.



Not sure which section this goes in.

Note that this is my first custom PC, so I may have done something wrong with the wiring, but I think it's fine.


Hardware first.
AMD Phenom II X4
XFX ATI Radeon HD 4870 512mb
Corsair TX 650W PSU
Asus M4A785D-M Pro AMD 785G
Patriot Viper 4GB Ram

So basically no output via HDMI or the blue PC port thing.
What's weird is when the monitor is disconnected from the PC, it says "NO SIGNAL", I plug it in and it goes into stand-by mode. Turn PC on, still in stand-by mode.

I've connected it to the blue PC port (don't know proper name) on the motherboard, and to the graphics card through DVI to PC converter. Still no output.

Connected a different monitor via HDMI on the motherboard. No output.
Graphics card doesn't have a built in HDMI port oddly enough, just 2 DVI ports. Monitor works fine when connected to PS3.

I thought the graphics card might be interfering with the MB chipset, so I reset CMOS and repeated what I did before still no output ffs. (PC is brand new btw)

Removed graphics card, connected monitor to blue port on motherboard. No output.

CPU (fan) is on, GPU (fan) is on. PSU is obviously on. Green light on motherboard is on.
Monitors were on when I tried them too, I'm not thick.

Also, when I press open on the DVD drive, it shuts again.
Also (2), keyboard connected via PS/2 port (only 1 port?), don't know if it's working, when I press caps lock it doesn't light up.


Sep 10, 2009
Hmm. Nothing comes to mind initially, since you cleared the CMOS. It would be hard to identify a wiring problem over the internet. How long does your PC stay on for after you turn it on? Will it stay on or does it quickly turn back off? If it quickly turns back off you may have something shorting the MOBO among other things.


I'm pretty sure the wiring is fine.

The PC stays on until I decide to switch it off.


Dec 28, 2002
Just a thought here. While in CMOS(BIOS) did you disable ONBD graphics with the 4870 GPU installed and are you plugging in both 6 pin connectors on the 4870?

I know if no connectors are plugged in the GPU you should get a loud long beep from your M/BD. But not sure how it would react with just 1 connector plugged in.

Just use the 4870 enabled in CMOS(BIOS) with both connectors plugged in and no HDMI. If this works I'd say you probably have a defective M/BD.

Good luck :)



I can't access the BIOS as nothing shows on the screen.
When I reset the CMOS I used the jumper on the motherboard.



Nov 4, 2009
exact same thing happened to my asus 785g .. except whenever i reset the cmos and re inserted the ram and 4890 gpu it started right up... well at first at least..but the gpu wasnt working.. eventually it got unstable and did the same thing again.. wouldnt let me get into bios or load win7 again.. ughhh .. frustrating.. then after dealing with all that.. BAMMM.. right back to no signal.. its driving me nuts.. but i got it in the shop right now.. i know some guys that own a pc gaming spot.. rebuilds pc's, x box's ect ect.. but i talked to him and he said he's running a stress test on it now.. personally i think it has something to do with the drivers.. when i finally did get it to post i downloaded the drivers but not all of em.. the mb driver cd's a little weird..(pay attention when downloading em).. you gotta click the top section for diff drivers.. but ya.. dont feel alone bud.. same things happening to me.. as soon as they finish up with it ill get back to ya and let ya know what the issue was.. hopefully i dont have to rma it.. eeeee :) /)

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