EVGA z170 FTW CMOS checksum error followed by no display

[Elvirth]

Ok, so I am helping a friend build a PC, and when we went to post test, the first boot only brought up a CMOS Checksum error screen. Had no keyboard plugged in, so turned it off and went to get one. Came back, tried to boot. It hung briefly on a B2 code, then beeped twice and displayed A2. I have tried reseating both sticks of RAM, unplugging the GPU, clearing the CMOS, etc.

I'm hoping to figure this out while I still have all the components here, otherwise I assume I should RMA the motherboard. I'd prefer not to if it's just something simple that I haven't thought of.

 

[pentium4inside]

Try swapping the battery present on the motherboard with another one.
If the problem still persists, RMA the motherboard.

 

[Elvirth]

Try swapping the battery present on the motherboard with another one.
If the problem still persists, RMA the motherboard.

I pulled the battery and tested it, it reads 3V. I'm not sure it's bad.

 

[Elvirth]

Small update, I pulled the components out of the rig and carefully connected only what I needed. It now will display, can access the BIOS as well. Interestingly, only one of my RAM sticks appears to be supported, but the BIOS is still registering the full amount of available RAM. It reads as XMP1: [serial number of stick #1], XMP2: Not supported.