I bought an DQ77MK last year and was able to use it for a few months before it created an electrical short near one of the holes for the CPU fan, leaving black scorch marks on the board and rendering the board defect. Luckily the CPU (4th gen quad-core i7) and memory appeared to be still functioning. I had one of those big CPU coolers from a well-known brand installed and at that time contributed it to that cooler, although I never had any problems with similar CPU coolers on previous Intel motherboards. So I ordered a new DQ77MK, and now, after running 24/7 for a few months, it starts tripping the power supply after a few hours. I replaced the power supply but the same issue exists. The power supplies have ample power, and the system ran in the same configuration for several months without a problem. I suspect an overload created on the motherboard, causing the power supply to shut down. The power supply comes back after a few seconds but the motherboard is locked up. I can restart the computer after some time, but a few hours later the same thing happens.
So I just ordered a third DQ77MK (for the time being this is the easiest to get my system up and running again without re-install of Windows 7 and all the apps). Wondering how long that is going to last.
I used several Intel motherboards over the years, and some of the have been running 24/7 for years without a hitch (including a motherboard with a gen-3 i7 quad core CPU.
Wondering if other people are experiencing the same problems.