I just updated the BIOS on my Crosshair VII since it was (about) 4 years out of date. I downloaded version 5003 from the ASUS website, extracted it, ran the included renaming tool and put it on a FAT32 USB stick. I put the stick in the "BIOS" USB slot on the motherboard, pressed the BIOS button and waited until it stopped flashing blue.
I came back about 10 minutes later and the lights were off so I powered on my system but it wouldn't POST, it kept giving a code of 22 on the display. Apparently this means a memory error? I tried reseating the CMOS battery after flushing out any residual power and some other troubleshooting steps, but ultimately it looks like my B2 slot is the problem. I can live with putting my two sticks in A1 and A2 and probably losing some performance as long as the thing works, but I was wondering if anybody has heard of this before or has any solutions.