09-17-2019 05:21 PM
Welcome to the forum.
I am not a HP employee.
A boot disk failure error message usually means the HDD may have failed. It could also be a loose HDD power or data connection.
I can't locate your PC using Pavilion A523x.
Checking HDD connections on a Desktop is easy. Checking HDD connections on some HP Laptops/Notebooks may require disassembling the PC to get to the HDD.
Try running HP Diagnostics (Link) to verify HDD failure.