Monitor receives no signal all of the sudden

I doubt the card would even function at all if it was not plugged in securely, but I don't know that for sure.

Perhaps the card is overheating after all. Try testing your GPU temps with Speedfan.

Thanks again Jonathon,

I have attached the capture of the speedfan reading.

Not sure which fan is which? Seems to be only picking up the mobo fan? I have two other case cooling fans and the graphics card fan which is still not working.

Temp 3 is concerning!

Considering the case is open and the room temp is quite cool, not sure what to make of it. Is there anyway to figure out which is temp3?

Try going to the Exotics tab, and click "Show the magic".

Perhaps that will tell you more.

Ok, here's the screen shot.

Still not sure where that temp is originating from but it is concerning.

GPU seems fine though

79C is a very high CPU temp, an unrealistic motherboard temp, absolutely not the hard drive temp, but for a GPU, it seems normal.

I honestly don't know what to say about that.

Perhaps the fan on the card only kicks on when the temperature reaches a certain point.

Maybe the card needed to be reseated, that's all. I guess we'll have to wait and see if the problem returns.

~JK

I was mistaken about the fan it has been on the whole time. I'm an idiot.

Shutdown computer. Restarted. No signal to monitor. Aargh.

I'm leaning toward faulty card (still under warranty thank goodness). If it was mobo, surely I'd be seeing the same issues with a different card.

As an aside, I thought mobos emitted a single beep when the computer is started. Mine doesn't and I don't recall if it ever did? I could be wrong though.

It depends on the motherboard, really. Mine has no speakers, so no beep codes ever.

On the family desktop, it beeps only when it encounters an error (no keyboard, hard drive, etc).

Hi Nina,
Internal speakers that produce the POST (power on self test) beeps are usually supplied, or built into the case at the time of build. If one isn't supplied with the case, they are often not added in by the system builder. Many people don't like the "annoying little beep sound" anyway so they don't miss them until they find out that they can be a handy little diagnostic tool :)
Your motherboard layout should look something like this, with an internal speaker (if supplied) connected to the pin header shown:

If you don't have one, I have a few spares here that I can help you with so don't stress!

The GTS 250 cards also need additional power from a y-adaptor cable, which should have been supplied with the card, something like this:

Make sure that it's securely inserted into the graphics power connector at the end of the card, or it may be suffering from power issues Under full load, your card should consume around 220W of power, so the 650W power supply should be enough, depending on how many other devices you have attached, it's component quality and actual power output.

I got distracted halfway through typing this post up, and my apologies if you've already tried this, but before you re-inserted your graphics card in question, did you give the contacts a little clean up first?
If not, it's pretty easy to do, but you do need to be careful...

Unplug the power cable at the back of the pc and then take the side panel off the case. Touch the bottom of the metal case to ground any static electricity from your body, then unscrew the graphics card retaining screw and remove the card while pushing the retaining clip in at the end of the PCI-E slot (if present).
Carefully put the card down flat on a non-metallic surface (anti-static bags from computer parts are handy for this).
There's a few products you can buy to clean the contacts, but if you're careful, you can use a clean pencil eraser. Gently polish the gold contacts on one side of the card, turn it over and do the other side, then use a clean, lint free cloth to wipe away any little rubber dags that are left behind.
Ground yourself again by touching the inside of the case, re-insert the card, ensuring that it's seated propoerly and the retaining clip is doing it's job, re-connect the y-adaptor power cable, connect the PSU power cable at the back, power it up and check it out.
Let us know how you get on :)

As Orpheous mentioned, check power cables are connected securely and you have the Y cable connected to the PSU.

iseeuu mentioned the possibility of a PSU problem.
What brand is your PSU?
Some brands don't give the power they claim and can decrease over time.
If you can borrow a PSU from someone you could confirm or rule this out.

thefabe mentioned checking the cables, did you try a different one?
Are you using the HDMI, DVI or D-SUB cable?

If your monitor has one of the other connections than your using now, try another cable.
This will rule out a cable or socket problem.

You can also check for a bent pin in the cable/socket your using now. Check that there isn't anything in there that shouldn't be, dirt etc.

With other cards working in your computer and your graphics card working in other computers (what cable did they use?), appears to be cable/socket problem or some issue with the PSU or monitor.