Well, that was way easier than I thought it would be. I didn't want to try the method mentioned earlier in this thread, on how to remove the retaining ring with the SAK screwdriver. Far too easy to damage the rubber button cover if you slip or just don't do it exactly right.
I already had a screwdriver that I sacrificed into a small chisel and made sure it was sharp as a knife before proceeding. I just put the head in my vise and carefully pried off the original retaining ring in about 3 seconds by easing the tip of the screwdriver/chisel under the outside edge.
Then I used a piece of leather and thin cardboard to protect the head while pressing the new retaining ring into place with my arbor press.
And all done!
Total time start to finish, about 5 minutes and that includes carefully smoothing out the burrs on the new retaining ring, where it contacts the rubber. It was super sharp and might have eventually caused an issue.
I recommend doing a burn-in test after swapping the retaining ring.
The retaining ring is held on by a friction fit. Removing the retaining ring will slightly erode the head of the light.
Aluminum expands when it gets hot. If you have replaced the retaining ring even once there is a chance that the ring will pop off when the head gets really hot.
To test: after swapping the retaining ring, turn the light on to turbo and wait till it gets hot. Double-click a few times to make sure it gets really hot (slightly hotter than the temperature protection would normally allow).
If the ring doesn’t pop off: Congratulations… you’re done.
If the ring does pop off: the head is eroded slightly. Add some super glue gel around the inside of the head where it touches the retaining ring. (I prefer Fiberfix optical super glue since it cures instantly). After waiting for the glue to dry, repeat the test. It should not come off with glue.
Family emergency kept me offline for several months, then I returned to find the D4V2. Took me 3 or 4 days to read every post in this thread. Now I think I’ve got to have it, and I’ll probably be posting my D4 collection for sale when I get time to take some pictures.
Reading this thread left me wondering about a couple of things:
(1) I see how the thermal-management code error made the light overheat when it came on unattended. But I apparently missed any comments describing why the thermal code error made the light come on in the first place, or why the unexpected turn-on was voltage-dependent. Are these things now understood, and considered in the fix implementation?
(2) There was at least one mention of a D4V2 getting hot when the battery was reversed, but I don’t think it generated any discussion. I realize that I never learned why the D4V1 reverse-polarity protection didn’t work - I’m just careful inserting cells. What exactly was done to “fix” the RP protection, and do we just assume the reported incident was erroneous? Or did I possibly miss a follow-up report?
Love the concept of the V2, got to have it. And while I bought 18350 tubes for all of my D4 and D1 collection, I regretted not getting the 18500 tubes as well. I’ll be buying both for this one.
I’m sure you will get a better answer but as I recall the issue came into being because of the new multi-color emitters. Implementing a sleep mode that could leave enough life in the MCU to color change also left the light trying to find the temperature while searching for low voltage protection in the off stage. This looped over and turned the light on. TK checked the light extensively but of course had no idea a 15 minute delay could cause a loop, she found it, rewrote the code in that area, and fixed the issue.
Reverse Polarity Protection is implemented on the driver through the diode, which only flows current one way. It should not have been possible for the light to heat up due to an inverted cell. Something else was going on that we don’t have the story on. A loose strand of wire or something, but it wasn’t due to the protection failing. A fail would be the diode fails and then the light wouldn’t work at all, correct installation or not.
Dale, is it correct to say there is a diode in series with the battery that was not present in the D4? I’d also assume this means the V2 is less efficient, more voltage drop, especially at higher current? And should this be noticeable as a “less powerful” turbo mode in the V2?
Or is the implementation such that the series diode only prevents activation of the driver, and is not in the FET high-current path?
Not sure how “less powerful” could actually apply as power potential is such a variable with different cells or even a dirty (not cleaned before installing) cell. Any potential loss would be undetectable to our eyes anyway.