Archived from radmon.org - originally posted 12/06/2023 I was asked by Gissio to try and download the original firmware from my HFS-P3, so I tried. Alas, no joy so far. ☹️ Under the battery (stuck down with sticky tape) is a pin header. Probably designed to have a pogo pin connector connect to it as there is no room to solder on an actual pin header. I just soldered wires to it directly. I managed to work out the pins by tracing the circuit, but I had to use my microscope as the connections on the MCU really are that small! I took photos of both sides and flipped one then overlaied one over
