Last night I assembled a single 18650 zoomie and a Convoy M1 both with an sst-40 emitter and mtnelectronics fet+7135 driver. I have assembled several other lights like this but both of these lights come on, flash twice, then turn off. I have bypassed tail switch spring on both. I have used a piece of wire to bypass the switch all together with same results, two flashes and done. Today another order of parts came in and I took the M1 apart and put a new driver in it. It still does the same thing, two flashes and off. Anybody got any ideas?? I feel confident in all my solder joints and retaining rings are tight and making good contact. Both have standard firmware with memory.
What battery are you using?
Iv tried Sony vct5 and Samsung 25Q.