The safest method is downloading the official BIOS SoftPaq from the HP Customer Support Portal . You can use tools like 7-Zip or specialized BIOS extractors to pull the raw binary from the official HP updater.
The HP Z240 typically uses a 16MB (128M-bit) SPI flash chip. Your BIN file must match the exact byte size of your physical chip. How to Safely Source and Use an HP Z240 BIOS BIN File hp z240 bios bin file high quality
Search eBay or Aliexpress: "HP Z240 BIOS chip pre-programmed Winbond 25Q128" . The safest method is downloading the official BIOS
You cannot use this file with a standard USB flash drive from the boot menu. You need an external hardware programmer (like a CH341A) and a SOIC8 clip or soldering equipment. hp z240 bios bin file high quality