BleepingComputer.com: POST w/ one video card but not another...why?

Specs: ASUS A8NSLI Premium
4Gigs Corsair XMS DDR3200
GTX550 vid card (new one) 7900GT (old one)
550W Rosewill PSU
AMD Opteron 165

So, I just got a replacement mobo and hooked everything up. Added my new video card (GTX550) and BAM...one long beep three short, same POST i got for my broken mobo. I tried my old video card (7900GT) and it POSTed FINE!!! I have a 550W PSU so it couldn't be a short in power...right? I have no clue why one card will work and another will not...I need help, bad.

Thanks in advance for your sage advice!

Hello and welcome to Bleeping Computer!

First off your BIOS beep code

1 Long, then 3 Short Beeps= Video error

Explanation: The BIOS is unable to access the video system in order to write any error messages to the screen.

Diagnosis: This is usually caused by a problem with the video card, or the memory on the video card. It can also be a motherboard issue.

Your PSU may not have enough output to properly power up the video card along with everything else in your computer system.
This can result in a lope boot where system restarts over and over again trying to boot properly, or a complete system shut down in extreme cases.

Sometimes an incorrect BIOS setting is the cause or a BIOS update is needed to support newer hardware, specially video cards that are added to the system during upgrades.

I am sure you double checked that the video card is properly seated in its slot when you installed it in the motherboard slot.

See if when you boot up the computer if you are able access the BIOS, hold down whatever key is mentioned on the screen.

You can make changes to the settings for the video card's settings and see if this corrects the problem.

If no post and no video is the problem, this can be caused by a defective video card (it does happen that brand new video cards are defective right out the box!)

If the video card was to work in another known working computer, then I would suspect your video card is not getting enough power from the PSU, it is being under powered causing the issue.

It could also be your BIOS just can not handle the card, I have seen cases where a BIOS upgrade corrects the problem, be advised that with computers with no display, you should perform the upgrade using a video card that works with the current BIOS version, then switch cards after the upgrade.

Bruce.

This post has been edited by MrBruce1959: 09 September 2011 - 09:55 AM

So I just read the min req for the video card and it says 400+W PSU w/ 12V rating 24A...I see on my PSU that it is 12V+ and - @18A....does that mean my power supply is insufficient? I have a Rosewiill 550V2-S-SL

To be truthful with you, it probably is insufficient.

You listed the PSU's output amperage at 18 Amps, the GPU requires 24 amps, you already have a deficit of 6 Amps right from the start.
Now configure the rest of the computer system's demand for available current, you fall quite short of the requirement.

Think of it as starting your automobile with a standard 9 volt battery instead of 12 volt one with 600 cranking amps, it's not going to happen, the supply is much less then the demand.

Your video card is struggling to get enough power to function properly, bigger cards require bigger power supplies.

You can skimp on the power to sound cards and live with it studdering, but video is a totally different situation, when your video studders, you get dropouts and video distortion or nothing at all on the screen.

Upgrading your PSU to one with 40 to 50 Amps on the 12 volt rail is highly recommended.

Bruce.

This post has been edited by MrBruce1959: 09 September 2011 - 08:19 PM

So I went and exchanged that card for one with GDDR3 which requires 18A and guess what...IT WORKS! All problems solved, computer up and running. Thanks again for the help!!!

You could of got a new better power supply rather then exchanging the graphics card.

SgtNoobert, on 09 September 2011 - 10:06 PM, said:

There you go as I said you were over the limit by 6 Amps with the other card, this one meets the output of your PSU and it works, but you are still very close to the limit and if demand gets too high from other hardware, you may notice a performance hit on your video graphics.

I am glad things are working Okay for now.

Bruce.

Probably when the graphics card itself is loaded then you might run in some problems. I usually don't suggest Rosewill power supply's because of there quality, you should have a look at Corsair power supply's or Seasonic.