If you are the legitimate owner and the above fails, your only option is to contact Microsoft Support with proof of purchase (receipt) for a paid out-of-warranty motherboard replacement.
Unlike traditional laptops, the Microsoft Surface Pro 4 does not have a removable CMOS battery or a physical BIOS jumper. Resetting the BIOS password is intentionally difficult for security reasons (to prevent theft). If you have forgotten the password, the solution depends on whether it is a User Password (set by you) or an Admin Password (set by an IT department). surface pro 4 bios password reset
Here is the content you requested regarding resetting the BIOS password on a Surface Pro 4. If you are the legitimate owner and the