@RemoNonaz I had similar issues (beeps, fan spinning on and off) with my i7-3770. Sometimes it would work several days without failing to boot, sometimes it would be many, many attempt boots before it kicked in and worked for a while. Once running it was stable until the next attempt to boot. My intuition (after about 38 years digital electronics and IT experience) was that the board was falling over extremely early in its boot cycle, whilst the CPU and memory timing was getting set up (duff values maybe? - a bit too close to the edge?)
Nit sure about the ME7/8 question, but following the flowchart will update the correct one, and that is one of the reasons that following the flowchart is important.
I doubt that the motherboard bios update process could kill the PSU, It sounds like bad luck. However fiddling inside a system, swapping processor, maybe even reseating motherboards in the case, it would be quite easy to physically short something out.
@stephenb.b.r Can you refresh my dynamic memory? (I now tend to forget things after a few nanoseconds! ) 
What was the three memory sticks issue? I'm currently using 4 x 8GB Kingston sticks in my system (32GB ram with an i5 CPU), Using Hyper-V on win 8.1 as an IT test rig (I had seven windows 2012 servers and two workstations running on it a couple of weeks ago ) Will the memory issue affect a four stick configuration with a newer BIOS?