I need help finding a replacement driver for my Astrolux FT03S. The light will only power on and and do no other functions. The only way to turn it off is to break the tailcap loose. I’ve tried contacting banggood and Mateminco, it was a waste of my time. I really don’t know that much about this stuff so any help would be greatly appreciated! TIA
Welcome to BLF 
I have modded a handful of lights and in the process of turning a few on the first time, they had bad connections and performed very similar as you described. The low voltage will make the driver behave oddly. I do not own an Astrolux FT03S. I would remove any oil from the threads and try to locate any possible weak connections.
Mateminco is the manufacturer so message them on AliExpress for a new driver