Need help diagnosing Nitecore D11 problem.

[300Z]

I accidentally dropped my D11 from a height of about 70-75cm head first into the tile floor and since then the light won't work properly. When I screw the head in the light comes on at minimum level and when I press the switch to turn it on/off the light will go to the highest level but as soon as I release the switch it will go back down to the lowest level, the light won't turn off and won't stay at the highest level, if I press and hold the switch it will start from high go down to low like it's supposed to and when I release it it drops to such a low level that I can barely see the LED is on, if I press the switch again it goes back to it's normal low.

I disassembled the head to inspect it and at first glance there was no obvious damage so cleaned everything up reassembled and nothing changed so I took it apart again and noticed that was something like some sort of glue on around the PCB and "glue" had come apart a little bit on one side and it looked like the outer ring trace was just barely touching the body, I removed the PCB and found out that there is another outer ring trace on the under side.
Now my question is the supposed to be isolated from the body, more specifically the under side? I know the side that faces the battery shouldn't make contact because that's what closes the circuit and activates the light when I press the switch.

Any clues? I love this light and would really like to get it fixed. Any help would be appreciated.
I linked 2 pics of the PCB.

https://1drv.ms/i/s!AvFATHfc37asluhryUUbIu6aQ6EWeA

https://1drv.ms/i/s!AvFATHfc37asluhpvKr0SRWma-ouRg

 

[swan]

The brass contact ring that sits on the spring that makes contact with the piston must travel freely. Push up and down on the ring to make sure it travels freely and does not bind or grab on the pill. This controls the ramping and if it binds or grabs it will play up as you described, you can clean it up with some emery or bearing scraper.

I really liked mine also but i dropped my one to many times and it shattered the bigger of the two coils on the driver, which broke the hair thickness wires that are two small and fine to solder.

The fact that it still lights up is good and has to be a contact issue-

 

[300Z]

The brass contact ring that sits on the spring that makes contact with the piston must travel freely. Push up and down on the ring to make sure it travels freely and does not bind or grab on the pill. This controls the ramping and if it binds or grabs it will play up as you described, you can clean it up with some emery or bearing scraper.

I really liked mine also but i dropped my one to many times and it shattered the bigger of the two coils on the driver, which broke the hair thickness wires that are two small and fine to solder.

The fact that it still lights up is good and has to be a contact issue-

The brass contact ring was the first thing I checked and it is fine...

 

[lightfooted]

Referring to the image labeled 004: The transistor at the 10 o'clock position seems to have a bad solder pad connection on the left hand side. I would inspect this closer...it may be the result of a short. There also seems to be some solder on the brass ring near the black wire in image 002. Perhaps that is interfering somehow?

 

[300Z]

Thank you, I'll look into that and re-solder all the components.

 

[300Z]

Re-soldered the components but it did not make any difference...
So is there any way I could mod the circuit to make this work again? I know I could probably just re-wire it to bypass the driver and have the LED be driven directly by the battery and use it as a twisty to turn it on/off but I would lose the lower levels, and can the LED work like this safely using a 14500 battery in case I don't have another option?

 

[LeafSamurai]

You sound like you can mod a flashlight well and I'm sure you can eventually figure out a repair on your own but have you tried emailing [email protected] for a repair? If it's within 5 years that you bought the light, warranty for it is still free and you only need pay shipping costs which I'm sure you would be happy to as you mentioned that you love the light. I know that it's discontinued but no harm in trying. You just need to wait and have a lot of patience once you sent the light for repair. Good luck and hope you manage to sort it for yourself.

 

[300Z]

I did think about sending the light out for repair but I'm in Brazil for the next couple of months and just shipping the light out for repair would end up being considerably more expensive than buying a new light.
I'm gonna open it up for another look and if it doesn't work I'm gonna modify it and just make it direct drive.

 

[lightfooted]

I did think about sending the light out for repair but I'm in Brazil for the next couple of months and just shipping the light out for repair would end up being considerably more expensive than buying a new light.
I'm gonna open it up for another look and if it doesn't work I'm gonna modify it and just make it direct drive.

When I mentioned the condition of that one transistor I was meaning that it may have been fried and is no longer functioning like it is supposed to...or more likely the controller chip saw voltage where it wasn't supposed to and may have melted something inside. It may not be possible to "fix" it. However if you haven't entirely given up on it yet...try doing this: with no power connected to it at all...use a length of wire to short every contact to the ground point where the negative battery terminal is connected. Again, DISCONNECT the power completely when you try this...and I do mean EVERY contact...just wipe everything on the board with the wire while it is connected to ground and hold it for several seconds.

I once...experimented... with my Nitecore P20UV...and got some interesting and not entirely desirable results. By disconnecting power and draining off all the possible charges by grounding everything...it started working like original again.

 

[300Z]

When I mentioned the condition of that one transistor I was meaning that it may have been fried and is no longer functioning like it is supposed to...or more likely the controller chip saw voltage where it wasn't supposed to and may have melted something inside. It may not be possible to "fix" it. However if you haven't entirely given up on it yet...try doing this: with no power connected to it at all...use a length of wire to short every contact to the ground point where the negative battery terminal is connected. Again, DISCONNECT the power completely when you try this...and I do mean EVERY contact...just wipe everything on the board with the wire while it is connected to ground and hold it for several seconds.

I once...experimented... with my Nitecore P20UV...and got some interesting and not entirely desirable results. By disconnecting power and draining off all the possible charges by grounding everything...it started working like original again.

Cool, I like that idea, I'll try it tomorrow.
Thank you.

 

[300Z]

When I mentioned the condition of that one transistor I was meaning that it may have been fried and is no longer functioning like it is supposed to...or more likely the controller chip saw voltage where it wasn't supposed to and may have melted something inside. It may not be possible to "fix" it. However if you haven't entirely given up on it yet...try doing this: with no power connected to it at all...use a length of wire to short every contact to the ground point where the negative battery terminal is connected. Again, DISCONNECT the power completely when you try this...and I do mean EVERY contact...just wipe everything on the board with the wire while it is connected to ground and hold it for several seconds.

I once...experimented... with my Nitecore P20UV...and got some interesting and not entirely desirable results. By disconnecting power and draining off all the possible charges by grounding everything...it started working like original again.

I tried this but that didn't help, so I just made it direct drive at least that way I have a functioning light, the only problem is (apart from not being able to change brightness level) is that runtimes on my 14500 battery is atrocious, I get maybe ~5min and the battery dies, but I never run the light for that long using a 14500 because the flashlight get very very hot too quickly, and it's way too bright for my normal usage.