Before flashing any binary file, you must verify the exact motherboard revision inside your HP Pro 3500 MT. HP used a couple of different motherboard suppliers for this series, and flashing the wrong binary file will permanently brick the board.
Go to the HP Customer Support page and enter your serial number or look up "HP Pro 3500 Microtower PC". hp pro 3500 series mt bios bin file
If the motherboard components interfere with the test clip signals, you must desolder the chip to flash it on a programmer breadboard. Before flashing any binary file, you must verify
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