QK Mechanical Keyboard suddenly stopped working

I have a QK65 keyboard. Was using it normally when it suddenly stopped working. I thought the battery just died, but pretty sure it was fully charged when I managed to connect it via bluetooth and check the battery for a while.

This was gifted to me so I dont really know a lot about keyboards. After doing a quick google search, I tried opening the case to clean it but still, didn't work. I tried playing with the magnets, and it actually lit up at some point. When I assmebled everything together again, I had to push the case down only to make the on indicator light up. After some time, it stopped working completely no matter what position I try with the magnets (if that is the problem). Please help me what went wrong?