SDH,
Ref: "Clearing and Resetting the CMOS" Pg. 160 : HP Z220 SFF, Z220 CMT, Z420, Z620, and Z820 Workstations Maintenance and Service Guide: http://h20628.www2.hp.com/km-ext/kmcsdirect/emr_na-c03424977-1.pdf
I cleared CMOS by > unplugging the z620> pressing the power button to discharge > waiting awhile> pressing the small yellow button for 5 seconds (No. 35 on the z620 system board diagram pg. 26 next to what I think is the UEFI module) > As soon as I plugged the system back in, the power light was on. > The system booted to a screen that prompted pressing F1 to configure. > I did so, it offered replicated setup and factory default. > I selected the factory default setup, > saved > and exited. >The system rebooted and behaved normally, and on the startup screen showed the BIOS as v. 3.90 to which I had updated yesterday. > A shutdown and restart confirmed all is well.
I'd panicked a bit yesterday as I saw a long post on corrupted UEFI modules having to be replaced. This is the first time in 20 years of using computers that I ever had an issue with BIOS.
All along, I've seen that the z420 and z620 are paired as far as BIOS version. It's interesting that the recovery disks that arrived with our two z420's both say that they are for the z420 and z620- but don't mention the z820. As mentioned, I had used the recovery partition of the later z420 to load Windows to the z620 and it did so without asking for any additional drivers and activated automatically.
Related Question: That the BIOS and system recovery software is the same for the z620 and z420, gives me some hope that I might use the z620 to setup a new C: drive for the z620 and a z420 simultaneously. The new drive is an HP Z Turbo Drive 256GB AHCI. My idea is to setup it up over two or three days in the z620 -it's a 16-20 hour process- then clone it to the Intel 730 in the z420, transfer the Intel 730 to the z620 and use the Z Turbo in the z420. The z420 is the 3D modeling system and the z620 is the analytical, simulation, and rendering system (replaces Dell Precision T5500). The same software is used on both systems, but only one iteration at a time. If you have any comments on this idea, that would be appreciated.
Thanks very much for your reply.
Cheers,
BambiBoom