GA-Z87X-OC - boot problems

[papoka]

Hi there!

I didn't have any problems with my GA-Z87X-OC until recently. One day they just started and it's like this all the time.

When I boot my workstation, the screen's black and the debug code is steady 15 or 15, 34, 35 - looping. Doesn't even boot to BIOS. Then, I can take out any RAM stick, turn on the PC (it turns on ok). After that I cant power it off, insert the same RAM stick and power on again - it works. It works just until the next turning on. It doesn't matter how many RAM's are installed - I always need to take one out to turn it on.

Did the Clear CMOS thing when I was looking what's causing all the trouble. Have also read all about the codes and issues folks have with them.

Can someone maybe help me optimize the BIOS so it's working ok again?

Specs:
- GA-Z87X-OC
- i7-4790k (non-oc)
- Kingston HYPERX FURY BLACK 1866 CL10 DDR3 32GB (4x8)
- 3x GTX980Ti EVGA Hybrid
- PSU LEPA G1600MA 1600W

Best,
Papoka

[shadowsports]

Greetings,
This behavior/errors is all related to the memory controller in the CPU.  If you have upgraded the BIOS recently, that's it.

If you haven't updated the BIOS, is your memory on the QVL for your board?  The 4790k is happiest with 1333/1600Mhz ram.  1866 Mhz memory is temperamental and typically requires OC to run stable.  The failure you receive at each cold restart is the CPU failing to initialize.  Pulling one DIMM is masking something.

Places I'd look:

Replace your MB battery
XMP settings in BIOS
Consider manually settings memory timings and voltages in MIT (BIOS)
If the systems runs correctly/continuously after booting into windows, installed amount of memory reported correctly, no crashes or BSOD, you don't need to test the RAM for errors.   
Last...
Check CPU socket for bent pins

Often, in these cases using manual settings, or slower RAM 1600Mhz usually helps.