Help with JETBeam BC40

So last night I tried to change LED on my stock BC40’s XM-L U2 to a XM-L2 T6 4C on 16mm Noctigon for better tint. However, the reflector base was too close to the wires so I ended up RE soldering a few times and I notice the head of the light was very warm/hot (I can still hold it). But the max is less than 50 lumens now vs 830 stock.

I put the stock LED back in, but still the same. Did the driver get damaged from the heat or the short when the reflector was touching the wires?

I can’t seem to get access to the driver either. No idea how it is being held in the head. Any ideas?

I have a BC40 but haven’t attempted opening it yet. It turns to low when you twist the head (facing forward) clockwise.

Could it be that the twisting hi-low mechanism was damaged when you did the soldering job hence its stuck in low?

I hope not, when tighten the head i get around 50 lumen, when I loosen it only around 10 lumen. So the high low setting seems to work. Just that both high and low is no where near as bright as before.

Edit: If some know how to get the driver out is fine too. Anyone know?

I’m sure it’s glued in.

Have you went back to the old emitter (or soldered on longer wires and ran a test bench emitter) to verify that emitter didn’t get damaged?

Yeah, I solder the old emitter back in. It was the same low output. I also tried it with and without the reflector on, no difference…

The annoying part is it has a integrated shelf and on the other side there is no place for me to put a tweezer in to unscrew.

Just to be sure, batteries read 4.17v on both. So only thing I can think of is the driver.

Hey D10ten, did you managed to fix or do anything with your BC40?
If you did get the driver out could you post some pictures of it, if you have some.


Yeah, I was finally able to open the head using a pair of strap wrenches. Turns out I heated the wire a little too much and the other end of the wire that connect to the driver almost came off. It was barely connected. So I guess problem was that a small connection cannot handle higher current. I pull the wire a little and it came off.

Since I got the head apart, I figure I wanted to put a XHP70 in it using a buck driver. However, the pill is only around 18 mm, so I will have to cut the sinkpad a bit.

Were you able to get any photos of the driver? I’m very curious. 0:)

It was the (LED +) wire. I have already solder it back on.

So the whole thing disassembles with just 2 screws, damn how didn’t I see that!

Yup, but I wasn’t able to take the contact plate on the battery side out yet.

It won’t come out voluntarily, they used generous amount of glue, same with BC40SE, have one with destroyed LED (I didnt get the driver out, yet, not sure if I will).