After having installed Linux Mint in my Windows partition I wanted to reset the device to defaults settings and partition so I reflashed the BIOS and it failed in the ending part.
I can how either press F7 and have the BIOS settings only or let the tablet boot and end into the Fastboot Mode.
Is there any way I can unbrick it without having to open and weld anything to reflash it?
Serial code is Q64G45160801959
Double check with CHUWI if you have the right bios that works with your system.
Then reflash again and see what happens.
Normally there is no need to reflash bios to reset a system to factory default
1 The bios has an option to return to defaults.
2 From a live Linux mint system you can use gparted to remove anything from your disk.
3 CHUWI can provide the factory image and tool based on your serial number to reimage your disk.
Here are the files;:
Sorry for the late reply, but it looks like forum’s email notifications are not working atm.
Unfortunately everything you and @ChuwiSpainSupport said didn’t work so it’s definitely software bricked. 
Now all I need is to find a (video?) tutorial on how to open the back and flash directly on chipset.
** Update **
Found it! 
WARNING: this will void your warranty!
Soooo it came out I didn’t actually brick my tablet lol! 
Basically to flash Android it is mandatory to use Windows 7 because Windows 10/11 don’t allow the installation of the INTEL DnX drivers.
In fact I had the flashing process always failing at 25% and wrongly thought I had f up the device!
Anyway I went with the WINBOND chip reflash then from a Windows 7 VM ran succesfully the Android flash and now I am dealing with having Linux Mint installed instead of Windows 10. 
