Vostro 3500 BIOS Update Failed - Recovery Procedure Needed

I had a working Vostro 3500 laptop and was doing maintenance to bring it up to date. I downloaded and installed the recommended BIOS update for this laptop... Dell Vostro 3500 System BIOS 3500A12.EXE | Windows/DOS (3 MB) BIOS Release date 7/21/2014 Last Updated 7/21/2014 Recommended The BIOS update failed and left the computer with no working BIOS. F2 is dead. It will not boot. I am pretty sure that there is a backup or primitive BIOS still in there, as when I start the machine with no battery and just AC power using the End key it continuously tries to read data from a 2GB flash drive. I assume that it would like to reload the BIOS from a file. I know how to get the ROM contents from the above file using the /writeromfile parameter. The big question is, what kind of file does the 3500 want to read, and what is the file name that it is looking for? Does the flash drive need to be bootable? Is this an AMI or Phoenix BIOS? Can someone please help? Thanks, Terry