Just received my TN31 and the ring control is so gritty that I find it very hard to turn from brightness level 4 to Standby. Feels like a pebble in there, that’s how hard it is to turn! I seen reviews on the TN31 and there are pics showing the control ring part removed from the head. I can’t get this part to come off and don’t want to force it. There is anything in this part that will resolve this problem?
You need to unscrew the reflector head from the body. Like in this picture. I never done before with my TN31. Some parts like the tail plate is glued to the host.
I just chatted with Thrunite on-line. I was instructed to return it to a US based dealer and a new one will be sent out. I just assume not to mess with it. I just got this yesterday too.
My ring is sloppy instead! Like it has too much freeplay, both axially and radially, about one millimeter. If I quickly tap it with fingers it rattles. Would be nice to have something like an oring placed inside to fill the gap.
I tried but cannot disassemble the head.
The tailcap had some threadlock but opened easily.
Same here but my guess is there is only .5mm freeplay. Just enough to rattle.
Sorry to hear about ya sloppy ring pal…… 
DON…