Question New build won't clear POST unless left on AUTO - Z790 Apex Encore + F5-8000J4048F24GX2-TZ5RK

[bman2084]

Losing my mind on this new build. 14900K + Z790 Apex Encore + F5-8000J4048F24GX2-TZ5RK

• Memory kit is on the supported list
• With all Extreme Tweaker settings left to their default "Auto" selections, the system POSTs and boots into windows just fine
• If I try "Manual", or any of the "XMP" options, the system refuses to POST (even at a reduced memory speed of 5600)

What am I missing?

 

[Tech Junky]

Upgrade the uefi and try again. There might be a bug causing the ram issue or the ram isn't fully seated. Xmp doesn't usually cause many issues unless you're base clock is higher than what's specified for the CPU already.

 

[bman2084]

The BIOS version? Upgraded to the latest already.

Strange thing is I can boot and install windows and use the PC if I just leave everything on AUTO. I don't think I'd be able to do that if it was a DIMM seating issue.

 

[Tech Junky]

It will run degraded if one isn't fully seated. I had one dimm die while swapping some gear and it would halt on a reboot. Just a thought since xmp is only ram related. Also ran into some oddities with AMD UEFI versions that run fine but, a warm reboot would hang. Maybe try another prior version to see if xmp will work. There are also some potential quirks if you have more than two slots in use.

 

[In2Photos]

It's possible that there is a problem with the RAM that doesn't show up until you enable XMP. Try running something like MemTest and see if there are any errors at stock settings. These errors may allow the system to run at stock settings but get amplified with XMP and cause the issue.

What voltage is being applied when you turn on XMP?

 

[bman2084]

Ran Memtest in the BIOS with everything on AUTO and got a ton of errors. I'm starting to think I got a bad kit.

 

[In2Photos]

Ran Memtest in the BIOS with everything on AUTO and got a ton of errors. I'm starting to think I got a bad kit.

Both Dimms or just one? You could run it with one until the new kits arrives if it's just one.

 

[zir_blazer]

If it fails at 5600 MHz and you got MemTest errors on auto, most likely the memory is bad.

Yet, 8000 MHz is on the borderline of the possible. You most likely need a binned Processor with a very strong integrated Memory Controller to actually get to that.

 

[Shmee]

Yeah, this just sounds like a bad kit. I would try RMA or return.