I had to deal with three of these boards today, and it wasn't much fun.
I set up a test bed earlier in the week to update the BIOS on two DP67DE boards, so I used it to work on the DZ77BH-55K boards. My test bed consists of an Antec 380W Earthwatts power supply, an eVGA GeForce 6100 video card, a DVD-RW drive and a Western Digital 320Gb hard drive with Windows 7 Pro installed.
The first board went through post, with BIOS version 57. I proceeded to flash the BIOS to version 97 (the most current available). The flash completed successfully, but the board then refused to post with error code 32 and three beeps. After changing out DIMMs, I ended up installing a single 2GB 1333 Kingston module in the slot closest to the processor. The system then booted and I was able to get into the BIOS. Following a recommendation posted earlier in this thread, I set the memory voltage to 1.6V and the System Attendant voltage to 1.0V, saved changes and rebooted. The system booted into Windows on my test hard drive with no issues. I powered down and replaced the 2Gb DIMM with four 4Gb 1333 Kingston DIMMs, and the system once again booted into Windows with no problems. However, the system will not post with 8Gb 1600 HyperX modules - it gives the 3 beeps and error code 32. I have ordered four 8Gb 1600 modules that Kingston lists as recommended for this board, so I will try those when they arrive next week.
The second board would not post at all, no matter what memory I tried. I also tried various recovery methods, using Back-To-BIOS and the jumper on the board, but nothing worked. I set this board aside to be returned to Intel. My customer told me he tried flashing the BIOS on this board, so I suspect that the flash went wrong and the BIOS is corrupted.
For the third board, I was able to boot using my 4Gb 1333 Kingston DIMMs. After some reading online, I decided to flash the BIOS in stages, using progressively newer versions as recommened by an Intel engineer. I started with a flash from version 57 to version 85, then rebooted, loaded BIOS defaults and tested by booting to Windows with no problems. I then flashed to version 91, loaded BIOS defaults and tested again. My third flash was to version 94, and then my fourth was to version 97, loading defaults after each flash. This system booted every time with no post problems or error codes. Windows also booted fine each time.
These boards do seem reealy finicky with memory. I'll be working on 7 more of them over the next couple of weeks, so I hope they go as smoothly as my third board did today.
Derek