8800 ultra killed two pc's!

[CuBixxx]

Hey, before I explain my problem here are my system specs,

Win XP
C2D 3.0 ghz
2 GB Kingston Ram @ 800 mhz
Maxtor HDD 200 GB
850 Watt Antec PSU
Intel DG33FB mobo

Basically I bought a 8800 Ultra last year and it has been working fine up until a couple of months ago when the monitor image kept freezing and then going black, needing a restart to get it to work again. This first happened during gaming, then it started happening more frequently until it was doing it whilst idle on the desktop. My first thought was that it was over heating but using Nvidia's monitoring software I was never getting over 55 degrees on load! (I have good airflow through my system) One day the monitor just wouldnt load any picture at all and displayed 'no signal'.

My next thought was to test the monitor as it had broken and been replaced once before, however it worked fine on another computer. After this I sent the card back to the supplier and they tested it giving it the all clear and I reinstalled it and it worked fine for a few weeks, then all fo a sudden one day I was getting no signal on the monitor again. Since then I have tested two other cards in my system, a 6600 and a 8800 GTX (a friends card) both worked perfectly fine so I can only presume its my Ultra that is broken. The problem doesnt end there, I decided to ask my friend if i could test my Ultra in his system as we have a similar system spec, it didnt work however after removing my card and reinstalling his, his monitor also shows the no signal when his card is in and no system beeps can be heard on boot up.

All cards were carefully installed with the power off to prevent circuiting and non of them have been over clocked or tampered with. Im now in the situation where the manufacturer will be replacing my card but I may also have to pay to fix my friends PC with money I dont have.

ANY advice would be much appreciated!

P.S I have checked all monitor cables and dongles for missing pins and they are all intact, I have also inspected the cards and mobo's for signs of damage and didnt find anything.

[Monty007]

Not Sure but I would install his original card boot in safe mode uninstall the video drivers and reboot, other than that I would go through and remove all the power supply cables and start installing the hardware from scratch.