Hi, I am using 3 ATI FirePro 2460 Multimonitor cards each driving 4 monitors & has mini DP slots. I have lost 2 cards in less than 5 months. I have used them for over 4 years with no issue. I am getting current ( Positive test light using a tester ) at the male tip of Mini DP data cable that comes from monitors & goes into the female slot of the cards. This happens only in two cables out of 12. Others no current. What does this mean ? Also I am getting minor shock when touching the chassis of the CPU. If I turn off the power of all monitors & keep CPU power on, then I don't get any shock. So definitely monitors are causing this problem. The power source to everything comes from the same one outlet. So what is going on & is this issue causing the graphics cards to fail ? These are all low profile fanless ( No cooling fan ) cards using just few watts of power.
Doesn't seem likely the fault is in the cables. If I were in your shoes, I'd try replacing the video cards originating the current. Also try swapping positions of the video cards on the mobo and see what changes. 1st thing you have to do is isolate the source... identify that then work on the fix. First thing that comes to mind is possible problem with a video card or a PCIE slot on the mobo. If you have any electrical issue, it could manifest in seemingly unrelated ways.
What happens when you distribute the power source and everything among "different" outlets instead of putting everything on one outlet ?
I have not tried it but here is what I am going to try & please tell me if it is the right way. I am going to connect all the monitors thru a different outlet. So CPU & monitors won't be connected from same outlet.
"I am getting current ( Positive test light using a tester ) at the male tip of Mini DP data cable that comes from monitors & goes into the female slot of the cards. This happens only in two cables out of 12. Others no current. What does this mean ? Also I am getting minor shock when touching the chassis of the CPU. If I turn off the power of all monitors & keep CPU power on, then I don't get any shock. So definitely monitors are causing this problem." I don't think the data cable should be feeding back power to the video card, the card is powered by the computer. Try disconnecting the cables you get a power signal from and in their place connect the other cables. See if you get a shock from the cpu. If not I think those two monitors have a problem, some sort of an internal short, a bad ground possibly, that is allowing juice to travel to the card frying the cards as they are receiving juice from the machine and the monitor. Are both the monitors the same brand? Just a thought, as scat said , diagnosing elec problems can be tedious.
I don't know if its the "right" way but something easy to explore via connecting you monitors thru a different outlet. I had a similar like issue and was lucky enough that the person I hired to maintain my network and configure my computers was quick to notice there was an issue with the outlets in my home...actually the wiring. I had to hire an electrician to re-wire my trading office even though I was already using different outlets.
Depending on how hard you're hitting the graphics card it may be overheating. I've run into issues where I upgraded the graphics card but the airflow in the main box was insufficient. The only way I could keep it safely cooled was to take off the side panel. In my case the GPU didn't outright die but would go crazy after a while.
All the monitors are same brand, Model & specs. Going to try your suggestion of changing the cables. Right now I have only one card connected because I am afraid of loosing the second card. I am not getting shock with this card & 4 monitors connected to them. So that rules out those 4 monitors & cables.
My office is air-conditioned 24/7 & air from conditioner is hitting the back of CPU so cooling is sufficient. The cards are not overloaded at all either.