glad youre exploring mode options with Memory
I can understand that 6 modes is overkill for your needs, but if the 30% is not enough to transilluminate, there is a 50% mode with memory in the 6 mode group, as you know.
my tool has never failed to turn on, sorry to hear you experienced that, and hope it does not happen again. Sounds like possibly a weak spring making poor contact pressure at either end. Not sure if stretching the spring slightly could help. I dont have a VN model, maybe yours already has a double spring, or would benefit from it. I speculate the heat of operation on high could have altered the spring pressure.
Im not the expert, and would definitely seek guidance from Vinh. And I would expect he will ask what your battery voltage is. Ive heard of people having batteries fail on high, and still work on lower settings. I suspect drained batteries in need of recharge in their case, though that may not be the cause of your failure to turn on. Making it no less disconcerting.. I hate reliability mysteries, until they are solved
enjoy your break from work.. and I hope the 30% memory mode proves effective for your application.