"Red light" problem solved, at least for me
I had similar "red light" problem with my 0805 mini dash cam. I used my cam for a year without any problems. But one day I started my car and my cam didn't start - there was only red light shining, indicating charging. Power button didn't work, I couldn't start my camera. I also tried to hold power button for 15-30s to perform hard reset, but no success. I tried starting it up with and without SD card, again no success. I tried to connect it to my PC, byt PC didn't recognize any drive. Tried many USB cables and chargers but it didn't help, only red light... I read many articles on this, looking for some solution. I thought there is a problem with battery. So I decided to perform disassembly of my cam (following one of the threads on this forum about disassembly). I did the following 3 steps: 1) opened the casing 2) separated the two curcuit boards inside and 3) measured the voltage (3.17V) between the black and red wire leading from the battery. Then I put all parts together and camera started working!! Miracle
Maybe separation of the two boards helped in my case.