Gimped TN11

The programming on a TN11 is a little weird but I got it to work initially. Now, my light will only go into turbo. If I attempt a head twist to get it into a programmed lower mode, it sputters, flashes, or does nothing at all . I tried reprogramming it to no avail. I am using AW 18500 x 2 with one extender to get maximum output and relatively compact size. The batteries worked great initially so I know it is not them. The light worked well in this configuration for two weeks. I also got rid of the extender and plopped in one 18650 and the problem persists. I have cleaned contacts and everything. I think I got a dud.
I should have got the G25C2 instead... in fact I still plan on getting one as it is almost as bright, can use filters, can candle stand with included rubber tail stand, and is probably more reliable.

Any ideas what to do with my Tn11? Right now it is a single function ( maximum brightness ) flashlight only.

Have you tried tightening the switch retaining ring in the tailcap? I find a loosened ring can lead to the problems your describe on TN10/11 series lights (as well as many others). A paper clip end should be good enough to tighten it.

A while ago, I had a similar problem where the mode toggling and programming via twisting the head was wonky, but fixed it right up.

Anyway, the "fix" involves taking some Q-tips and cleaning out the "rings" on both the head and the battery tube. These "rings" make contact with each other whenever the light's head is tightened, and when the contact between the two is broken the light enters the secondary output mode. What happened with my TN11 was that the lubricant (which is electrically conductive, by the way) used on the threads somehow got between the contact rings, preventing them from properly breaking contact and failing to signal the light to change modes. This is probably the case with your TN11, as well.



Give the two rings some swabbing and you'll see that there will be some sort of gray grease. This is the lubricant. You can use alcohol to clean the rings thoroughly, but make sure not to clean lubricant on the threads themselves. Otherwise, you'll need to re-lube the threads to prevent damage.

Thanks very much your replies, guys. With renewed hope I eagerly followed your advice. Alas, it still doesn't work properly. This light did work originally, and I was able to successfully program it every time I tried. This is something beyond cleaning I'm afraid. I contacted the dealer and will be sending it back. Thanks again for your replies. Hopefully my new one will be better. I will also get a G25C2!
Cheers

This is indeed weird. Had a while ago, something like this problem too with the TN11.
Only that was, like selfbuilt says, a loosen tailcap ring.

Mine did the same thing exactly, I think Selfbuilt hit it, my tail switch was loose. A minor cleaning & relube and tightening of the switch made it like new, the TN11 switch has a tendency to get loose when you uncscrew the tail cap. Good luck.

@OP - as selfbuilt and others mentioned, it's most likely due to the tailcap switch being loose. However, it might not be obvious that it doesn't follow the standard "righty-tighty, lefty-loosey" rule and must be tightened from inside the tailcap counter-clockwise (take care not to over-tighten it though as the aluminum threads are soft). Check reply #45 for pics (and apologies if you already did know this).

Hope that helps,
Tim

Yup... thanks again. I checked, and the tailcap switch is very tight... doesn't want to budge in either direction. Still doesn't work. I will ship this away tomorrow.
Cheers