Greetings,
Welcome to the forum.
I am not a HP employee.
A 2:2 BIOS error indicates BIOS corruption and no recovery binary image is available.
You could try the following BIOS Recovery steps (Link) but the MB may be toast. There may be a recovery BIOS image on the HDD if the HDD has a HP_Tools partition.
I would also swap in a new CR2032 MB battery for the heck of it. Inexpensive and will not make things worse.
HP also has a 4-1 USB key (Link) with BIOS recovery options but in your case it would be putting the cart before the horse. But it could be useful in other troubleshooting scenarios.
Regards