No display on monitor (but I get a signal) with an Nvidia 7800GT

By heimdelight
Aug 13, 2010
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  1. This is my first post ever, so I'd like to say hello to everyone on Techspot (been kind of a lurker), and I'll keep the whole story short,

    Yesterday my best friend began to move away for college, and his computer was going to be passed down to me. It's in near perfect condition, and the only thing we had to replace before starting it up again was the power supply. His supply before was a solid 400, and the one we bought is a 450w.

    We bring it back to his house, replace the power supply and voila! The computer is running.

    So it continues to run perfectly fine, we play games on it and make sure everything is smooth, and it is. Start -> Shutdown. We bring it back to my house.

    So we plug in everything, and we're about to start it up. My buddy presses the power button, everything goes on, but the monitor remains black while still receiving a signal.

    His nVidia 7800 gt gfx card has it's fan running, which would leave me to assume it's running fine. it's NOT the monitor. I've tried other monitors and they get a signal, but its a black screen. The monitor also works on other computers. The gfx card has two HD ports, and my friend had two converters for them so not just an HD monitor could run on it. I've tried different combos of cords/converters and could not figure out what is wrong.

    Any help is appreciated, thanks!
  2. mailpup

    mailpup TS Special Forces Posts: 6,964   +355

    Try reseating the graphics card and while you're in there double check all data and power cable connections for tightness. It's possible something came loose during the process of moving the PC.

    If that doesn't help, maybe the graphics card or possibly the power supply has failed. Even though it can provide some power, the PSU might not be able to provide enough total power. Just because a part is new doesn't mean it can't fail. What power supply did you buy and what are the other components?
  3. heimdelight

    heimdelight TS Rookie Topic Starter

    We bought a 450W BFG Power Supply, and it says it has a 3 year warranty (that's relieving..)

    I wish I knew more about computers. I know he has an EVGA motherboard, and a Cooler Master Fan (which I know doesn't help).

    I re-seated the gfx card and checked for any loose cables/connections and everything is working fine.

    Another possible problem could be that when his original power supply failed, his secondary monitor was a giant HDTV. Since then the use for that TV has changed, but when we originally started up the computer at my house last night we had it plugged into the secondary monitor slot. We put it back in the #1 slot quickly, and that's when we realized our problem. Could it be that the resolution is at an incorrect size and the monitor can't display it?

    And when his previous power supply failed, the whole computer wouldn't boot. In this situation, everything looks like it's receiving power (the gfx card's fan is running, motherboard lights are on, cooler master fan is running, etc..)

    EDIT: Learning more as I go along on the subject. I have another monitor that has an HDMI port, S-Video, HD, and VGA. I tried every kind of connection with the video card possible and still no display. The monitor is an acer monitor, and it has a blue light that turns on when its active and displaying. However, when the PC boots now, the light is orange (like a stand-by mode or something, no signal?).

    It's starting to give me a headache. Should I try switching out the graphics card with another and figuring this out from there?

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