I have a separate USB3 card so I just disabled the internal USB3 Controller and the problem went away. (Another option that also worked sometimes was to remove a ram DIMM and/or move it to a different slot, forcing the system to rebuild it's cache and clear the error to at least a bootable state where I could reset the bios to factory defaults.Īnother glitch I found is that the internal USB3 controller doesn't get turned off on shutdown, so what happens is that the Z820 never really shuts down, but actually it reboots on shutdown and shows an error screen on OSX boot.

The Z820 read from the drive, but I doubt it wrote/changed anything in the bios itself, but at least it wiped the NVRAM clean and the system came back to life. The only way to get it back from a 'bricked' state was to switch the crisis recovery jumper and power on with a USB2 thumb drive (smaller than 1GB formatted in MSDOS MBR with a copy of the Bios.bin file in the top directory).

also no way to reset the bios, CMOS reset, disconnecting power, etc. The NVRAM gets corrupted and you can get stuck with a black screen, fans spinning but no bios splash screen. Since it was a new build I decided to give OC a try and found it works but with a big issue. I was going to sell my Z820, so I erased my system drive, but after the deal didn't pan out, I decided to keep it for now, so I rebuilt my system drive, and found a couple of things.

CHK Rus 3.96 for mac instal