It’s definitely something in the tailcap. I can get it to do it but pressing hard for the 2nd stage and usually get full brightness. If I slowly reduce pressure on the switch, it goes into low Incan mode. After that regardless of how hard I press, I do not get full high mode. Even twisting the cap fully. I need to unscrew the cap to lockout mode, then back in and sometimes that works until I manipulate the Tailcap again. Could it be dirty contacts in the switch? I cannot see a way to take it apart. Even a search doesn’t show much without destroying some parts. Spray it inside the tailcap with electronics cleaner?
Ah ehhhhhh…… it was the batteries….
The person I got it from believed they were new. No problem I wasn’t expecting any but I thought I’d have more runtime left. They were easily able to power an s2+ with
sst-20 at 1.4A on high so I figured they’d still have plenty of capacity for the regulated circuit. But no. Put in a fresh pair of cells and problem was immediately fixed. Put the old ones back in, and back to low Incan mode. Also with the new batteries, the leds were clearly brighter. Well now I know what to look for