Help needed! Courui modding issue (permanent on)

Flashlight Modding and DIY Parts
1

I have modded this Courui since 1 month ago but it is not perfect yet as some issues still presented.

What I have modded:
Removed the stock R200 resistor and drop a solder blob in there to achieve direct drive in high mode.
XM-L2 on Noctigon.
Change the LED wires into 22AWG.
Battery springs are copper-braided.

What is the problem?
The LED was still lit even when the light was switched off! Refer to the picture below, it looks like some sort of “moonlight mode”, very dim but it is actually lit and it does flicker a bit.

I did some connectivity test using my DMM. When I used the probes to touch the LED +ve pad and the pill, no connectivity was found.

However when I touch the LED -ve pad and the pill, the DMM gives beep sounds, which mean the pill has connectivity with the LED -ve.

After that I tried to connect with a 18650 battery. The -ve end of the 18650 goes to the LED ve and the +ve end of the 18650 goes to the pill some sparks came out, it is indeed shorted!

Before this I thought it was the LED or Noctigon problem, so I change into another piece of LED but problem was still persist.

BUT, when I remove the driver and leave it tangle outside the flashlight, the aforementioned shorted issue gone. From here I guess it is actually the driver problem.

I try checking if I has soldered anything wrongly on the driver but I couldn’t figure out anything. This driver works with an electronic switch and I am not quite sure about its mechanism. Some photos of the driver as below:

To make it more understandable:
When driver was put on, issue presented (permanent on and shorted occur between the LED and the pill)
When driver was left outside the light, no problem at all.

I have no clue at all but is there possibly something has burnt or shorted in the driver? Hope somebody can help me on this. :frowning:

2

Check all the wires. When everything gets twisted to get tucked into the driver something may be shorting.

I noticed what looks like some solder from the LED + wire may be connecting with ground.

3

I think you may have found the problem! Let us know what happens when you clean up that solder joint.

4

Oh well, thanks for the input Ouchyfoot and Richard. I will go back and try this tonight. :slight_smile:

5

Jut clear that one, it was actually not solder but some dirt. I used a tissue paper to rub it off but the LED still lit when switched off. :frowning:

6

Remove your bridge made of solder and see if the problem vanishes with it. One step at a time, revert it back to 100% stock original until you find the thing that's causing it.

7

There is an electric current in your driver.

Maybe you have to change it.

Xandre

8

It’s not directly related to my problem but I guess it can be some damaged components on the driver as I refer to the Fandyfire Warrior thread. Refer to the post #334 & #335.

Let’s say if this is the case, so does using the stock driver as a contact board and mounting a Nanjg 105c on it can solve the problem?

9

I think this causes the problem,I have done 3 times this mode and no moonlight

10

I just got this light today… ( wonder why I wait so long to get this :slight_smile: )How do you guys take the driver out? does it come out easily?

11

Shouldn’t put up much of a struggle. I try to get a hook like implement into one of the two holes in the driver board. Then tug or tap it out.
You could also remove the led shelf from the front and then just push the driver out that way. It’s not glued or anything.

12

Thanks… can’t wait to mess up mod this light :bigsmile:

13

I have sold my Courui to a friend at a cheap price last year, so I cannot further investigate this issue anymore.

But some other has discovered that the “moonlight” was actually due to the bridged sense resistor. It is not advisable to bridge sense resistor like that.