I think my GPU is dead.

Most likely yes, it could be dead. Make sure your psu is in good condition and is delivering enough power. (1) If you can, you should test your card in another system and see what happens, also restoring it to the default clocks could help. (2) A gtx 560ti would be a nice upgrade, and a OC'd q6600 should handle it with no problems.

What power supply? How old?

Your Q6600 at 3.1 will run pretty much any video card.

somehow i knew it was an nvidia card before opening the thread  

could be the psu. could also be too much heat. 280s are quite hot and heatsinks loosen up over time, also fans get slower, gum up or die.

-It could be the power supply, in the bios, see what the hardware monitor is saying, the 12v rail should be over 11.7volts. 11.9volts to 12.01 is ideal. If it "hunts" goes up and down over 0.05volts then it could be bad caps. It normal for the cpu voltage to hunt a bit.

-It could be the overclocked Q6600, sometimes the memory controller will make errors, try dropping the memory speed to the next lower one. The pcie bus also follows the fsb on some boards.

BFG was known to factory overclock their cards so they would be on top in benchmarks. Usually this is fine, but sometimes this can cause a card to crash.
BFG is not the only one to do this, many cards come factory overclocked.

-First try setting the fan to manual at 100% and clocking it down a bit for the mem/core. See if that fixes it or not. If not you will have to try and increase some voltages.

-I have fixed a few damaged hd4870's, When cards get older sometimes they develop troubles. (mostly the hd-4870 doesn't like to run at 81C)

http://www.insanelymac.com/forum/lofiversion/index.php/...

GPU-Z (to see what your temps/voltages ect are)
Winflash (to save the original bios and flash the card with the modded one)
TechPowerUp Radeon Bios Editor (to mod the bios)

- Clean the heatsink/fan first, sometimes taking the fan and heatsink off, washing the heatsink with dish soap and water, and after it's dry reinstall everything with new heatsink paste helps.

-It's a good idea to get the system to boot from onboard vid, or a pci video card because if the flash fails you wont have any video. If you have a crossfire/sli board then you can just boot from another pcie-16 card.

-In the driver control panel set the fan to "Manual" and find a fan speed that is not too noisy, something like 35%-40% on most cards. See where your 2d idle temps settle out at, write the fan speed and temp down.

-Save your bios, then open it with the editor,

-Try modding the fan/temp first before upping voltages and dropping clocks.

The fan speed and temp you found in manual before, set the fan min to this, it will have a x/y chart, Put the temp that the fan starts to ramp up at that temp on the chart, then pick a temp max maybe about 70C to 80C.

-Flash the card and try it, if it is too noisy you have to increase the temp max a bit, if you think you can go with more fan speed lower the temp max to 60C or 65C.

-If the card still glitches in games, try lowing the memory and gpu clocks a bit (you can just do this in the video overclocking settings)

-If it still glitches go back into the bios mod software, start out with the one that you fixed the fan with so you don't have to redo you fan settings, increase the gpu and mem voltage to the next higher setting (not all cards allow this)

Well good luck.

thanks for the input thus far.. I will check my psu tonight and post back (I have, up to now, neglected looking to see if the PSU could be faulty )
.. it is a "Spire 750w" http://www.hlcomputer.com/750W-NSpire-PCI-e-PS-60522.ht... its probably at least 4 yrs old?? I dont remember.. (I tinker too much)..  

thanks again for your friendly help guys!!

Speedfan, says my "+12v" never goes below 11.97, (also checked in bios, and got same) so it looks as if my psu is ok.. While I would like to be able to game a bit until I can afford a new card, I dont want to baby a card that is on its last leg.. (by trying to turn everything down (making it even more antiqauted).. I cant afford the best cards,, but i need one that at least runs ok..  

as far as temps, they seem pretty average for the 280,, I watch temps close,, I have always had my fan at 100% all the time,, about a year ago, I removed the heatsink, cleaned, and reapplied Arctic Silver 5 High-Density Polysynthetic Silver Thermal Compound. this lowered the temps by 3-4 degrees c.

as far as the oven trick,,

7. If still not working and you are getting artifacts on POST, strip everything off card. so its just the PCB,
8. Put it in pre heated oven (about 220 deg c) for about 15mins.
9 Rebuild
10. Test
I have read that once before but didnt put much faith into it,, I would be willing to give that a try for a short-term fix.. has anyone had any success with this???? If so,, please give details,, (I didnt think 220f would soften solder, 63/37 solder becomes completely liquid at 361°F) anyway,, if this has worked for anyone, id like to know!

the oven fix is for dead cards, that have a broken solder joints. thats not you i dont think. wouldnt work at all if it was. oh, and just because your psu can supply the card with enough power during desktop operation, doesnt mean it can for gaming. check your psu with a gpu stress program running

if thats an 8800 gtx, its not a great deal slower than the 280 tbh.

unless you dont consider 33-50 percent better peformance a great deal (which i do) your statement is pretty false

really, never knew it was that much of a differnce, in that case, i recant

http://www.xtremesystems.org/forums/showthread.php?2007...

sorry for the derailing this thread.

the oven fix is for dead cards, that have a broken solder joints. thats not you i dont think. wouldnt work at all if it was. oh, and just because your psu can supply the card with enough power during desktop operation, doesnt mean it can for gaming. check your psu with a gpu stress program running

as I stated:
several days ago,,, the post sceen, (before windows) had bright green boxes here and there,, and when the windows loading screen came up the were two sets of verticle green lines, and My system no longer recognizes My video card at all..

i cannot run any 3d aps at all.. including furmark or any games.. but at normal desktop and boot up,, the psu is deffinatly doing its job and the card is definately not,, and while I cannot say with 100% certainty that my psu has no problems,, I can certainly say that the problem is not just a psu problem...

at this point,, I am going with dead card,, I may try to plug it in my buddies comp and see how it acts.. thanks again for all your guys help and advise..

solved

sooo,, I pretty much gave up and decided it was dead, then said,, what the heck,, (nothing to loose) and preheated the oven as I began stripping the card.. I baked the card at 250 f for 15 minutes, turned the oven off and let it slowly cool in the oven, as to let all the joints reharden before anything got touched..

long story short.. all symptoms of trouble are gone, and windows recognized the card again on boot up.. just now furmark tested it and it looks fine looks fine .................... HOOODA THUNK IT!!

Hats off to Cygone!! and thanks again to everyone...

(I will still be upgrading this card soon, as I still have little faith in the long-term effectiveness of this, but for now,, it has brought my card back from the grave,,

Best answer selected by dperkey.

Thanks for the daily laugh. That's like comparing aluminum to silver.

I'm starting to get all these symptoms on my GTX 460. In addition, there seems to be having some kind of a liquid on the PCB here and there. Thought it was coz of a faulty RAM and ordered a new one few days back.