Hi,
HP Support is flaky at the moment. HP is upgrading the support system.
Did you jump the gun when updating the BIOS? You have to let the system complete the BIOS update or problems can occur.
I can't find a eight beep code but a two beep, two beep cadence means the BIOS is corrupted and no recovery binary image is available. This can happen when updating the BIOS.
You may have to contact HP Support for factory service if this conditions persists.
Regards