Need advice for problems with M20

Hi everybody , I have sold a Olight M20 Warrior R2 and I had no problems with this light but the new owner have problems.
I can't help him , I need the expertise from this forum , I put here the questions he ask me,

I'm experimentig some problems whith your flashlight, and I really hope you can help me.
As I used with the 18650 (Ultrafire 18650 3000 mAh), I noticed the damned "low voltage signal", and, if I try to change level until a few seconds are passed since It blinked, I experienced problems in changing level. But if I wait 'til it flashes, it works fine. The real problems, comes out when I use rcr batterys: the rcr tube is really tight, and it's really hard to insert or extract the batterys. But when I use the 2 RCR123, I can't use the flashlight.
Just let me explain better: I enter the tube with the 2 rcr in the m20 with the head tighten, and if I try to switch on the flashlight I get no answer. The tailcap seems to work, but the led doesn't turn on. If I I loose the head a little, it works on low level. If I tight the head again, the m20 turns off. So, if

I try to change level, I simply turn on and off the flashlight.
At the beginning I though this was due to a circuit's bad contact, so I cleaned with alcool the battery and the circuit. I got the same problem. I changed RCR battery (I took another couple of Ultrafire RCR 3,7 V 800mAh), or use Primart Cr123. The same problem, even removing the CR tube and using directly the batterys.

Hi everybody.
I'm the buyer of Stienke's M20. Sorry for my english, is not my natural lenguage.

I partially solved the problem, keeping trying: the error was that I fully tight the head when I wanted to change level, instead of partially tightening the head. Doing This way, I can use all levels.:twothumbs

Asking me why this could happen, I discovered another thing. If I lean it (turned on) against the table (as shown in the picture below) and press the tailcap as indicated with the big arrow, instead of turning off, it changes level.




Why this happens? Simply because if the head isn't fully and hardly tightened and you "compress" the flashlight's body and head, there's a little movement, that's interpretated by the circuit as a changing level signal.

It's not a big trouble, but is an inconvinent.

Only my M20 has this problem?

have you try tightening the retaining ring in the tail-cap? see below:

you can use a tweezer or needle-nose plier to do it. if tightening down doesn't do it, try take out the retaining ring and the switch, clean the inside of the tail-cap, and carefully put them all back together.

Hi, I unmounted the tailcap, cleaned it and put all together.
That was really better, but the problem remained.

After I cleaned the head circuit with alcol, it works fully.


Thanks to Stienke and rookiedaddy

Great to hear your problem is solved!:thumbsup:
Enjoy your flashlight and thanks CPF!