Lenovo Y50-70 efi entries obsolete

[cocotugo]

hi, I am new to the bios/uefi world.
My laptop stopped recognizing usb as boot device. then i messed up the efi partitions trying to fix the usb entry.
fortunately i had installed linux and was able to boot  using grub2. is there any way to fix the uefi boot entries?
i've tried reflashing the bios update from lenovo but it just restarts the pc and does not flash anything.
and efibootmgr in linux throws errors (efivar installed and efivars mounted rw) 

Thanks for taking your time to read my post. I'd appreciate any suggestions

lenovo bios update: https://download.lenovo.com/consumer/mob...cn43ww.exe