stuck in Mini ORom Display boot screen as ASCII Legacy BIOS, I can't go back yo UEFI GUI screen

[Delaz]

My refurbisched Z640 is stuck on the Mini ORom Display boot screen,  in Legacy ASCII BIOS mode.

I can't switch back to UEFI because the GUI isn't activated by Esc or F10 (or any other Fxx key, Ctrl+P, etc.).

Secure Boot and TPM were disabled,

The BIOS was set to legacy instead of UEFI to access the RAID utility.

I have used the utility in ASCII mode (Ctrl+I) to access the RAID BIOS, but I now go back or boot from an SSD, a USB flash drive, or a CD/DVD 

(Previously, the USB flash drive and CD took priority over the SSD/HDD in the boot order.)

I had already installed Linux on a TurboZ SSD drive on a PCI slot before,

but I've since removed it to see if it was the problem. I just left a memory stick in slot 1. Whether it was on or not, it doesn't change anything.

The problem is that I can't go back to the GUI to reset the UEFI mode, and it no longer boots in legacy mode (even with the HDD RAID removed).

I know there's a CMOS ROM saved with the factory default settings, and I have jumpers on E15 pins 2-3 BBR, jumper of E49 removed (the passwords were cleared before the problem).

E14 is free. and seem to be useless until not unclocking the motrher board

If I short pins 1 and 2 of the E15 to flash a new M60_0261.bin file from a 1GB FAT32 USB drive via a USB 2 port, the LEDs blink 8 times, then the BIOS tries to access the drive, but nothing else happens except for infinite boot cycles and the lack of the update GUI that should appear.

I'd love if anyone knows how to resolve this legacy ASCII BIOS issue to re-enable a proper factory CMOS configuration.