No beep, no display, when turning system on.

[ereed]

Ok, I installed everything for the computer.....I installed the Win XP OS, installed the drivers, restart the computer and now it does not show anything on the display and no beep from POST. Everything powers up, fans running, lights on, etc....but doesn't boot up. You guys think its my mobo bad? Also one other question.....when installing a fan on a computer you have both a 4 pin and 3 pin.....I plugged the 3 pin into the motherboard chassis fan, and plugged the 4 pin to power supply....you think that caused the problem or I only need one cable plugged in and not both?

[flanzig1]

If the fan has both connectors, connect ONLY one. Use the 4 pin from the PSU.

[Cricket]

Follow the troubleshooting instructions found here. You must remove the motherboard from the case when doing this...you're trying to determine if the motherboard is shorting out to the case.

Cricket

[freakitchen]

Regarding the fan questionl some fans come with both 4 and 3 pin connectors, because the three pin is simply used to monitor the speed of the fan. If the 3-pin connector has only one wire attached, then there should be no problem connecting it in addition to the 4-pin.

FK

[ereed]

The fan has 2 wires to the 3 pin...I connected both the 3 pin to mobo and 4 pin to PS....you think that messed up the Mobo. I'm gonna try to see if I shorted the mobo...and if I did, that means I have to get new mobo right?

[ereed]

Also I'm running 2 gt7800 video cards.....I have 24 pin from PS to mobo, 4pin atx from ps to mobo, and cable from ps to each video card SLI.....my next question is that on my asus sli board I have where it says EZ plug connector, am I still supposed to connect cable from ps to ez plug connector on mobo? If I need to list every part I'm using in the computer then I can so people can get idea what I'm running. I'm going to try to do the mobo out of the case tonight and post some results. I think maybe my cables might have short the mobo or something so I want to make sure I have all the cables installed or at least what I need.

[freakitchen]

In that case, connect only the 4-pin. Shorting out the motherboard shouldn't have killed it, it will just prevent booting. Post back with the results after following the steps in the thread Cricket linked to.

FK

EDIT: In reference to your most recent post, please do post all of your system specs.

[ereed]

I'm going to do the steps tonight when I get home. By the way I didn't kill the mobo because all the lights come on the mobo and the fans, everything is running, cd rom opens/closes, just that the mouse and monitor isn't working or get signal or no beep. I'm going to do the steps tonight....can't wait to see whats wrong with it. Oh yeah by the way, I have another fan on my case which both has 4 pin connector, one has 2 wires, other has 4 wires...which should I use to connect to other fans? Sorry, I'm little dumb when it comes to wires. hehe

[ereed]

ASUS SLI mobo
Leadtek gt7800 video cards (2)
AMD 64 x2 3800 cpu
corsair 2 gig memory
aspire turbo case
antec 500w PS
Samsung dvd ram drives (2)
floppy drive
Seagate 160 gig sata hard drive
5 cooling fans

As far as power wires go....24 pin from PS to mobo, 4 pin atx to mobo, cable from ps to each video card, cables from ps to each drive

[ereed]

Ok, I followed the trouble shooting instructions, have mobo on box, only power cable attached with memory, video card, etc....everything powers up but no beep or display. Could this be bad mobo?

[Cricket]

At this point it's hard to tell which component is the actual problem...you just know it's one of the core components (power supply, motherboard, CPU, RAM or video card).

I would try to verify if that power supply is working properly by installing it in another computer.

Cricket

[ereed]

Ok, since I have 2 7800gt video cards I tried one card at a time both on each SLI connector and got no results, so it can't be the video card.....the motherboard is getting power and leds from power supply and I doubt its the PS since it worked on another computer.

[ereed]

I think I'm going to get another mobo and see if that solves the problem. But what I don't understand is that it was working perfectly after I built it and went into bios and I installed xp and drivers, turned it off, turned it on and doesn't post. Weird huh? By the way the mobo is ASUS A8N-SLI Premium.

[ereed]

Maybe I should just get another cpu and PS from compusa just to see if it works and then take it back. Is this best way to test since I don't have another computer handy and this one is OLD which is Pentium.

[glc]

Please use the Edit Post function instead of posting reply after reply. Thank you.

[ereed]

Ok, I got it fixed!!!! It turned out to be the mobo so I got new one and it fired right on up. Boy...building computers can really be a pain in the ass sometimes. Thanks for the help everyone.