7320 usb and fingerprint print scanner not working, please help

Hello all. I'm a newbie here and wondered if anyone can offer advice?

I bought a second hand but fully working Latitude 7320 i5 the non detachable version.

I used the Dell update tool and it updated a few things and the bios, now I can't use the USBs or fingerprint scanner, 😕 the USBs supply power but no data.

From my research it seems the bios could be the issue and even though not recommended by Dell a downgrade maybe required. The problem is without USBs how do I do this, I was thinking perhaps flashing the bios from the internal SD card reader? Please can someone help, I'm not massively experienced with bios issues. Any help is greatly appreciated.