The one I bought looks very much like yours. I had a wire break loose from while riding on a gravel. It went from light to no light though.

I was able to access the circuit board by pushing on the wire after I removed the handlebar mounting base. The plate behind the light slid forward until the circuit board was exposed. I found the broken wire and re-soldered it. It works fine now. The wires are extremely thin . It was fairly meticulous to solder the wire and keep the solder from reaching the other wires. I used the solder that was already on the circuit board and remelted it at the wire.