Any suggestion ? I have a z170 evga classified 4 way board which ran fine up till now it has an I7 6700k cpu and 16 gig of corsair ddr4 CMK16GX4M4B3000C15  ram. when booting up the system there is no post no beep nothing and goes right to code 42 and I can not find a code 42 in the list. I removed the board from the case with nothing connected but CPU fan, I checked the pins on the CPU seem perfect, removed the ram installed one at a time and tried a different power supply with still the same results code 42 no post or beeps. every so often after sitting unplugged it will boot into the cmos I did a bios update and after it updates it reboots and back to the code 42. I am now stumped. I even removed all the ram to get the beep warning and nothing again just goes straight to code 42.
Louy

bob16314
Z170 POST Code 42 is OEM post memory initialization..You can search around for various causes/solutions which may be the mobo is bad, but at least you know what the code means now.

I'd try clearing CMOS using the second method described here if you haven't done so already..Also try the other BIOS (that mobo has a Dual BIOS), and make sure the BIOS chip is fully seated too..You'll find the BIOS switch and removeable BIOS chip locations in the mobo manual.

Thanks I did check the bios seems to be seated OK it did pop out when I opened the clam cover I reseated it and cleared cmos. I did talked with tech support today he seems to think its the CPU memory allocation issue. i find it strange that if it sits a few hour it will boot into cmos but after reboot goes back to the code 42.

bob16314
May put a new CMOS battery (CR2032) in it, just for kicks.

Worth a try thanks

Ok great thanks for the input i'll let you know how it works out..