DQG driver issues

I modded a dqg 26650 to quad xpg2 running 2s2p. It was working fine. I tried to tweak it a bit and had a snowball of fixes that needed doing. One of which was a new driver retaining ring as the old one was a bit loose. Now it has no modes, it turns on in turbo and turns off but nothing in between.

I have removed the driver from the light to test and it works as it should but when reinstalled it’s turbo only. Really frustrating.

At one point I discovered if I unscrew the head just a little so the connection is kinda poor then the driver worked fine, screw it tight and it goes to turbo. I haven’t been able to replicate this though.

Any idea what might be causing this?

It sounds like a short somewhere. I had a shard of wire I could not see by the naked eye across an isolator that shorted to earth when I screwed the bezel down that last tenth of a turn. The only way I found it was with a loupe. Good luck with the fix.

Definitely a short, most likely a ground short. Off hand I’d take a good look at your new driver retaining ring.

I was thinking that would be the answer :weary:

I’ll have to get out a magnifying glass I think. I can’t really see it being the retaining ring because, well, I can see that side of the board when it’s installed, there’s not much can go wrong on that side.

Thanks, I’ll keep trying.

Send it to me, I’ll take a look at it… :wink: :smiley:

Yep, I’ve got an S8 I modded that behaves like that — high brightness only when I have the pill screwed in all the way; back it out a quarter turn and I have all the proper qlite selections.


OMG I found it.

I changed the spring, switch, switch wires, retaining ring, removed the driver from the light numerous times, installed new driver, tested with different LEDs (2 and 3 series) outside of the host - all successful. I even put liquid electrical tape around the driver to isolate it from the head. Still it didn’t work properly but just by chance I didn’t solder the negative lead to the LEDs properly. It came off during testing but the LEDs were still flickering. Damn it, the whole time the t-pad board was earthing out. I removed the screw securing the board and presto, works fine. I didn’t even think to remove that screw as I wanted good heatsinking since it was turning on straight to turbo.

Huff, chalk this up to just another screw up :confounded:

:person_facepalming: I’m just glad it was happening to you this time and not me. :slight_smile: Glad you found the issue.

Glad you figured it out. :slight_smile:

Always the last think you look for isn’t it? lol

Hate it when things go awry like that. I built an MT-G2 light and found very weak performance, rebuilt the driver and did all the other prerequisites to no avail. In the end, I had been sent a 9V MT-G2 instead of a 6V one. Aaaaaaaaaghh!

Awe that would’ve driven me nuts :confounded:

Come to think of it, this drove me nuts :stuck_out_tongue: and a wrong vf led would’ve been harder to pick.

This always reminds me of something that “Data” in Startrek-TNG used to say (hint: Sherlock Holmes) :)…