You know what you did, I don't.
Replace the CMOS battery.
Set BIOS to Optimised Defaults and the correct date / time, then make the necessary adjustments to install / run OS X.
Try booting from your USB instead of the hard drive.
Try booting with the Nvidia drivers disabled (boot argument nv_disable=1)
Try booting to recovery and run First Aid on the drive.
Try booting in Safe mode.
So, I got to change the battery and first got the new graphic of Happy new year from Clover, then set the clock and date right in the BIOS, put all the settings as optimized for Hackintosh setup, then saved and exit and got the Merry Christmas graphic again, then tried to run the boot and got the GPT/test/test/GPT/test/test message.
So I went into the BIOS again to find other info and found that the BIOS was seeing 2 UEFI, the OCZ-VERTEX4 and the USB Hard drive that we originally used to make then the boot loader in the VERTEX4 SSD.
I removed the Vertex hoping it would have start the boot loader from the USB stick, but got the message
"Reboot and Select proper Boot device or insert Boot media in selected boot device and press a key"
(I guess the lot of you are kind of laughing badly at these attempts but I am not giving up, I will fix this boy)
I have tried to switch the USB stick to other ports but nothing changed
Any further steps I should follow?
I can say for sure the version of clover was never updated from the original installed, that I can say for certain. I think I might "involuntarly" tried to update the macOS by pressing "Ok" instead of "cancel" in a rush to do something else on the machine.