(SOLVED)What's wrong with my new Convoy M21B?

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jwsm
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(SOLVED)What's wrong with my new Convoy M21B?

In turbo mode(100%), the light flickers(slight but definitely noticeable) and if I leave it on in that mode for more than 10 or 15 seconds, the light will start to blink(goes off then back on again) every 4 seconds. This blinking “mode” have also been triggered while in medium(3%) and high(30%) settings. It doesn’t happen all the time but when it does, the only fix is to loosen the head while the flashlight is turned on until the light goes out and then retighten it. May take more than a few tries but the light will eventually “reset” and start working normally again. It is a great little flashlight, when it works!

The batteries I’m using are brand new, fully-charged(measured 4.2V) Samsung 50E 9.8A 21700 cells that I got from IMRbatteries.com so it isn’t low battery voltage that is causing the problem. Does anyone know what’s going on with my new toy? Do I have a defective unit?

Edited by: jwsm on 01/08/2020 - 23:05
Yokiamy
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It might be caused by the retaining ring in the tailcap which needs to be tightened

jwsm
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Thanks for the reply. I have checked the ring in the head and tailcap and they both are on pretty tight. I have sent Simon a message and am still waiting to hear back from him. I am hoping it would turn out to be something simple that is easy to fix. I really like this flashlight and would hate to have to send it back to him and wait another month for a replacement to arrive.

The_Fat_Controller
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Flickering is usually not enough amps , bad connection or weak battery , you sure its a genuine cell lotsa fakes floating about, fakes will generally give normal voltage readings but take S**t when you try to pull full current

jwsm
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The_Fat_Controller wrote:
Flickering is usually not enough amps , bad connection or weak battery , you sure its a genuine cell lotsa fakes floating about, fakes will generally give normal voltage readings but take S**t when you try to pull full current

The flickering only occurs in Turbo setting(100%). Batteries used are Samsung 50E 9.8A cells which I got from IMRbatteries.com, which is a reputable seller so I’m pretty sure they are genuine. At this point I’m thinking it had to be a bad connection somewhere either in the head or the tailcap.

mikesz123
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jwsm wrote:
The_Fat_Controller wrote:
Flickering is usually not enough amps , bad connection or weak battery , you sure its a genuine cell lotsa fakes floating about, fakes will generally give normal voltage readings but take S**t when you try to pull full current

The flickering only occurs in Turbo setting(100%). Batteries used are Samsung 50E 9.8A cells which I got from IMRbatteries.com, which is a reputable seller so I’m pretty sure they are genuine. At this point I’m thinking it had to be a bad connection somewhere either in the head or the tailcap.

Main tube is not reversible so make sure its in correct position, mine had similar problems and i noticed it was screwed wrong way and reversing it fixed it. Also u can check if spring bypass has not detached and there is no cable floating lossely

Kevin Z
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Wait for it to heat up ,the flickering may stop .

SIGShooter
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If you haven’t already done so try cleaning the threads. Also do you get the same symptoms running it without the tail cap?

jwsm
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SIGShooter wrote:
If you haven’t already done so try cleaning the threads. Also do you get the same symptoms running it without the tail cap?

I had figured the problem was probably caused by a bad connection because any setting higher than low(0.01%) would often trigger low battery voltage warning(even though battery was fully-charged) and/or flickering so I cleaned the contact areas on the tube body and also the retaining rings with isopropyl alcohol and that seemed to have done the trick. I am guessing it was grease getting in the way and causing the bad connection issue. Anyway, the issue has not come back since and the light seems to be working fine now. I would like to thank all you guys for your comments/suggestions. You guys are awesome!

hank
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I am guessing it was grease getting in the way and causing the bad connection issue

Could be someone mistakenly used a nonconductive (high dielectric) grease and spread it on too thick.

jwsm
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hank wrote:
Quote:
I am guessing it was grease getting in the way and causing the bad connection issue

Could be someone mistakenly used a nonconductive (high dielectric) grease and spread it on too thick.

Don’t know what type of grease(whether conductive or non-conductive) Convoy uses on their flashlights but I have always thought that non-conductive(dielectric) grease is the right type of grease to put on the threads.

caramba
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jwsm wrote:
Don’t know what type of grease(whether conductive or non-conductive) Convoy uses on their flashlights but I have always thought that non-conductive(dielectric) grease is the right type of grease to put on the threads.

I am not familiar with the M21B but in the past Convoys and similar flashlights had 2 types of threads,
Anodized and Non-Anodized which are at the Tail and Head respectively.
One supposed to be non-conductive and the other conductive otherwise it would short the body.

I think Teflon aka PTFE type lube is being recommended which is dielectric.

Silicon type lube and Petroleum lubes are not recommended because they might degrade Latex or non-latex O-rings.

By the way I am not sure what the Prop65 status is on all these PTFE lubes, they might be dangerous to your body but not sure.

Edit: This lube brand is being recommended in lot of threads Super Lube.
I will order the Model # 60004 seems to be food grade H3 for direct food contact. Silly