Z390 Phantom Gaming ITX/ac with i7-6700K£

I got myself this (used) motherboard along with a brand new i7-9700K. Unfortunately I can't even get it to POST. Fans and cooler do start but everything turns off after a short while, only to try to boot again and so on, again and again.

A reasonable assumption would be that the CPU is the new R0-stepping and as such won't be recognized by the motherboard unless BIOS is at least v4.00. The sticker on the motherboard does say p4.00 though so I'm a bit puzzled. Maybe the former owner downgraded it at some point. What else could it be£ ( The build can be seen at https://pcpartpicker.com/list/D9qpLP ) .

My second question is whether an i7-6700K would work (even if it isn't listed in the CPU supported lis). I need some other cpu to get it to boot so that I can update the BIOS (if that turns out to be necessary) and this is the only 1151-cpu I've been able to get hold of right now.

In this thread an ASRock official says that "Z390 platform mainly supports Coffee Lake CPU." and that "when 6700(Skylake) CPU is used, it will not work properly".

Does this mean that it may work partially, although not perfectly, but at least sufficiently for me to be able to update the BIOS£

Afraid not, the 6700k is not supported. If memory serves there have been attempts
to run Coffee Lake CPUs on older 200 and 100 series boards with mixed success but
no one I know of has succeeded in getting Skylake to work on 300 series boards.

Make sure you do a full CMOS clear:
http://forum.asrock.com/forum_posts.asp£TID=630&title=how-to-clear-cmos-via-battery-removal

It may be as simple as the board was used with a much different CPU and has retained
some incompatible settings. The method I linked above should clear out anything
left over from it's previous config completely.

hmm ... it replaced the question mark there too..

Ok, just what I thought.. So shorting the two pins on the battery connector would essentially be exactly the same as pushing the button then£ In that case I've already done it..! :)

I think I'll remove the CPU to see if there is any bent or broiken pins on the socket. Nothing else comes to mind right now.

Xaltar wrote: Actually, no, the battery connector pins have nothing to do with clearing CMOS. On most boards there is a separate set of jumpers for clearing CMOS. If you didn't use the momentary switch on the rear IO, give it a shot. Also, shorting the battery pins wouldn't have hurt anything incase you were concerned.

Ok, well I've already tried that, keeping the button pressed for at least a minute or so.

I also removed the cooler and cpu to check for any damaged/bent pins but couldn't detect any.



I think I'll take everything apart tonight and start from scratch but first I'll try with some other memories I had the chance to borrow.