So I bought a 7970 a couple of months ago and had been mining a combination of litecoin and bitcoin.

I'd put the card into my old(ish) desktop running a 430 watt power supply (yeah, not so bright). I did a little overclocking and all was well.

Things ran fine for a couple of months then yesterday I started to look into how I could push more out of my card. I modified the settings slightly and got significantly more output (from 550khs to 650-700khs with litecoin).

All went well for about an hour, when there was a loud electrical shorting noise, lights flickering and all the usual things you dont want to see happen.

I'm thinking that the extra power drain that I placed on my 430 watt power supply was too much and it couldnt handle it. I must have been sailing pretty close to the wind before I tweaked it, so I wouldnt be suprised if it was just too much. I replaced the PSU with a 500 watt one that I had lying around and the computer now boots and runs fine, except when I try to mine.

I've restored the card to factory default and every time I start mining the system resets within a few seconds. Its possible that the new PSU isnt up to the the task either and that is the problem, but Im concerned that I've done some damage. Obviously, this is only a short-term fix and I will buy a decent PSU on Monday.

Does anyone have any suggestions about how to test whether my card is damaged?