In the repair world, we call this a "corrupt BIOS." The good news is that the HP Z240 is nearly impossible to kill permanently. The bad news? You need a to bring it back to life.
A BIOS bin file (binary file) is an exact, sector-by-sector copy of the firmware stored on the motherboard’s SPI flash memory chip. For the HP Z240, this file contains: hp z240 bios bin file high quality
Would you like help extracting a BIOS BIN from an official HP SoftPaq, or assistance with recovering a bricked Z240 using a hardware programmer? In the repair world, we call this a "corrupt BIOS