UltraFire WF-502B modifications - learning how to do it.

[Rufusbduck]

So…. I guess when every the driver detects low voltage it will drop down to low mode so the battery doesn’t drain completely…

Exactly, and a weak solder connection, a bad switch, or even jostling the battery against weak springs can fool the driver. Any connection that can be temporarily broken can cause this. Instead of trying to solder that larger spring to the brass post, remove the small spring from the driver and as ouchyfoot says solder the larger spring in its place with the small end on the board. Can you post a pic of the solder joint between the driver and the pill as a cold joint here could easily be the problem.

[satow]

@Rufusbduck

So…. I guess when every the driver detects low voltage it will drop down to low mode so the battery doesn’t drain completely…

Exactly, and a weak solder connection, a bad switch, or even jostling the battery against weak springs can fool the driver. Any connection that can be temporarily broken can cause this. Instead of trying to solder that larger spring to the brass post, remove the small spring from the driver and as ouchyfoot says solder the larger spring in its place with the small end on the board. Can you post a pic of the solder joint between the driver and the pill as a cold joint here could easily be the problem.

I think you are right about the pill. I was looking at it and the solder joint broke…

[satow]

@WarHawk-AVG

bronze? It’s solderable, but it’s a larger chunk of material so more heat is needed (use plenty of flux too)

It looks like aluminum plated with some kind of brass… strange…

[bushwhacked]

Your progress is great. After looking at your pill and seeing that it’s hollow I’d suggest getting a new one.
Having thermal paste under the MCPCB is pretty important and that pill seems like it’s all air.

I’m not sure where you can find a pill only, dropins are around 2~3 dollars. If you’re in Canada I can send you one.

[satow]

@bushwhacked

Your progress is great. After looking at your pill and seeing that it’s hollow I’d suggest getting a new one.
Having thermal paste under the MCPCB is pretty important and that pill seems like it’s all air.

I’m not sure where you can find a pill only, dropins are around 2~3 dollars. If you’re in Canada I can send you one.

Thanks! Yes the pill is hollow. It’s gold or brass plated aluminum. I used a file to clean the edge that is near the ground ring and the gold came off and showed silver. Unfortunately I don’t live in Canada, but thanks for the offer neighbor!

To make a better connection, I took a tiny piece of #3 solder wick and stretched it and stuck it between the driver board and the pill, and soldered it to the driver ring. It is making a very good connection between the driver ground ring and pill. Unfortunately after this, it still exhibited the same problem.

I disassembled everything, and left the driver board connected to the emitter.

I connected the battery directly to the emitter to test it. It was really bright. Direct drive. No problems.

To test the driver board I clipped a test lead from the battery positive to the spring. From the battery negative, using a test lead, I can touch the ground ring on the emitter directly and make it go thru the various modes.

However it still exhibits the same problem. When I leave it on high, after a few seconds it drops to low.

So it doesn’t seem like a problem with the grounding to the pill.

Maybe I fried something on the driver board….

But that’s okay. I am not upset. It is part of the learning curve.

Thank you everyone! This adventure has been very educational.