Hello everybody.

This is my first post on this forum. I've found quite some good informations in here, so I thought I'll just sign up and ask you pro's for some help...

I am trying to fix my three years old Fenix LD-01 for the second time now . The error is basically the same, the solution, obviously, is not. But let's start from the beginning:
When the Fenix stopped working for the first time, I could only get some light out of it twisting and pushing/bending it quite hard. My first thought was that the lower case didn't make a good contact to the PCB, so I added some solder to add up some height to the contact.
Unfortunately this made things only worse, because the irregular surface added lots of switch bounce, driving the mode selector mad .
So I went on and completely disassembled the Head. I cleaned the electronics from epoxy, took the PCB stack apart, and resoldered each and every component. After putting everything back together, it actually worked fine again. Up till now, about three weeks long.

The actual problem now is this: When I turn the LD-01 on, it eventually starts to flicker uncontrolled for a couple of seconds. During this flicker, it manages to cycle through the modes until it ends in high power mode, where it continues to work as expected. Turning it off and on again, restarts the flickering process until it ends in high power mode again.

So here I am now, ripped the whole thing apart again and wired it up do so some testing. The solder joints all seem to be OK now, I can't produce any misbehavior through knocking or pushing anywhere on any of the parts. I noticed that the core of the coil is broken, though. So I replaced it with another coil I had lying around, for testing purposes. This stopped the inductor whine (since I used a coated one ), but nothing else changed. Tried the same with the capacitors, but to no extend.

A bit frustrated and not knowing what to do anymore, I started drawing a schematic, as good as possible. While measuring the connections, I tried to check for bad vias, but everything seems fine to me.
Maybe some of you guys recognises which kind of driver is used and/or has some tips for me what else to look for.


Thanks in advance and kind regards,
Lasse