How did I delete the modes? What happened?

Flashlight Modding and DIY Parts
1

Ok, I have a Solarforce L2M host with a XML2-Dropin from DX, which has three modes. I added some strips from a soda can and some thermal paste for better heat transfer. The dropin has a smooth reflector. So far so good.
Now I also have a cheap 502 light with a standard XML and 5 modes. It has nothing but some thermal paste. The dropin has an op reflector So far so good.

I wanted to change the reflectors (op to XML2 and smooth to XML). I put the XML2 dropin back in the SF host and guess what, it didn´t work anymore. shortenign the dropin with a battery and a wire, it worked. I´ve put it in and out of the host several times and it did not work. After some cleaning it finally worked, but it has ONE mode only now?! I´m not sure, but I´d guess it´s high.
How can this be?

It even gets more weird. The other dropin, the XML1 now has ONE mode only AS WELL! What the?
What happened? I love lights that start always on high, but I´m not sure about one mode only …

2

LED negative is shorted to the reflector.

3

See if the reflector is in contact with the (-) side of the PCB, that would bypass the driver and give you only a single mode. Strange this is happening with both of your drop ins…

4

Umm, what was the LED negative again : >

5

Both PCBs have some pretty big solder spots. I did not make them. Might this cause it?

6

Test the bare pills with the reflectors removed. LED negative is the negative wire from the driver to the LED, just as the name implies.

7

The bare pill works fine with a battery and a wire and it changes modes. WITH a reflector it does nothing but lighting up with always with the same mode.
I don´t get it. I´ve changed springs, reflectors and even PCBs before and this never happened. And I don´t know how to prevent this problem : /
I mean, it is normal that the big (golden) spring has contact to the reflector, right?

8

The solder pad on the top of the pill, the one going to LED-, is shorting to the reflector when it's assembled. Prevent the reflector from touching it and it will work again.

These drivers regulate the current and control the modes by interrupting the negative connection between the LED and ground. Battery positive goes straight through the driver PCB and is always connected to LED+ at all times. So if LED- is shorted to ground by the reflector, it's the same as if the driver weren't there at all and the LED was connected straight to both ends of the battery.

9

Make the solder joints on the star smaller, kapton tape on the underside of the reflector. I almost always short the reflector on my first reassembly of a mod. :stuck_out_tongue:

10

use a pair of micro shears and cut the top off of the solder blob then add kapton tape

11

Or a dremel to grind them down.

12

Or find or make an isolator disk.

I have some thin transparent plastic that I got from old packaging material for something. I cut a small disk the size of the star with a hole in the center the size of the LED. Insert this disk over the LED and under the reflector. It completely prevents shorting through the reflector.

13

Lucky you, it could touch the other one and turn your springs into nice pretty rainbows that no longer reach the cell, pretty, but no worky. :wink: And that’s if it doesn’t fry the switch. Then you get nice smelly smoky yuckiness.

14

You need something like this

or use gaffer tape. Don't put it directly on the LED-base. Use two pieces, put the glue-sides together and now use a hole punch to make a LED hole. Cut the edges round and you have a nice isolator.