I just grilled the Giesemann LED light and Bluetooth module. I thought they use the same power adapter, both are 12 V, but boi was I wrong. One has plus on the outside of the plug, the other minus. Not the LED light nor the Bluetooth module have any indication of polarity or a warning on it.
While I "should have" made sure to get it right, that my friends is poor product design. I'm sure I'm not the first, let alone last one to run into this trap.
I sent Giesemann in Germany an email on Sunday. Well Monday went buy and they didn't respond. I asked for simple instruction on own to fix it myself. It should be done with replacing a couple diodes on both items, but I wouldn't be surprise if they skipped things on the circuit too.
If I don't hear back tomorrow, I'll call. If they don't offer any help, I'll look into it and see what I can do. If I can't fix it, I'll take it to the range next time around and put some S&W .500 Magnum 700gr hardcast through it, take photos and upload them here for everyone to see. And then I'll buy another 2 EcoTech LED lights, the same one I'm using on my refugium tank in the kitchen. Love those lights!