Quark AA2 died - DIY fix possible?

My 8 year old Quark AA2 ( R5 Edition 1 - according to the invoice) has just died. Not unexpectedly perhaps. Forgot it was in my lap and it dropped about 2 feet onto a wood floor when I got up from a chair. The problem appears to be in the head since the batteries and tail switch test OK. I would hate to just toss it out so I thought I'd take it apart to see if there was a clip, or contact or solder joint that may have loosened/mis-aligned. Is that even a possibility? Trying to disassemble the head I got as far as what's shown in the photos. Can the pill(?) be popped or screwed out? If so how exactly? At the moment I'm somewhat wary of going further since at this point nothing seems to come apart easily. I'm particularly concerned about breaking the solder joint of the white wire to the aluminum tube. I haven't been able to find anything via google or the forum for this particular model. Any thoughts, instructions or information sources on how to disassemble it would be greatly appreciated. Many thanks.

You have it in as many pieces as it comes. The white wire isn’t soldered directly to the Al head, it’s soldered to a screw, it shouldnt be a problem for you if you’re reasonable decent with the iron.

I have a QP2L-X with a Nichia 219b 9080 and Mtn Electronics FET-7135 driver.

OK. New to all of this. From what I've googled about led flashlight heads (and please correct me if otherwise) ... there is an emitter/led disk (shown in photo), below it is a driver PCB, contained a separate "pill"(?) all contained in the black head tube assembly(in photo) for alignment with the reflector and lens.

Cereal_killer... are you saying this is a far as I can readily go, but by de-soldering the red black and white wire I can get at the driver PCB/pill? If the driver and/or led are faulty, can either/both be replaced with new/"improved" components? Thanks.

No there is no pill in this light, the led board is setting on a shelf (integrated into part of the body. This is a good design compared to a pill BTW), the driver board is connected via the wires (and some glue in this particular light) underneath.

Yes both led and driver can readily be replaced with different components however note 2AA boost driver selection is non-existent in the size you need. You’d have to consider other battery setups, perhaps one 14500 plus a dummy cell, that’s what I’d do if I was looking for easy / cheap. That or go for a low drive current MT-G2 and run a pair of 14500 with a great driver / FW (now that would be a sweet revive of a cool old light!!)

Great! Thanks for the description of how the head is put together and possible fixes.

Good thing I'm retired and have the time. I'm sort of getting into this. Dollars saved flew out the window hours ago. It's the challenge now.

But, can I really go any further? The led tested OK so the driver is the problem. The aluminum heat sink disk (?) below the led disk appears to be a force fit (glued/epoxied?) into the head. Tried to yank it out with needle nose and only managed to scratch it. Similarly, the driver (assuming that's the other side of the battery contact disk) also appears to be a force fit. I suppose I could possibly drill/machine them out. Anything less brutish? Would kind of like to inspect the driver to understand why exactly it failed.

Thanks.

The aluminum you scratched isn’t a disk press fit in, it’s part of the head, it doesn’t come out! You’ll need to try to [gently] remove the scratches before assembly.

The driver is the green board you see from the other side, you’re right, it is glued it (shame on manufacturers that glue their stuff)…

Take a sturdy but small diameter tool (pick or something similar) and press it down into the wire holes to press the driver out the bottom. You’ll have to apply enough force to overcome the glue. Note it’s likely you’ll physically break it removing it.

Joy!

I used a very small micro screwdriver inserted at an angle through the screw hole (photo below). This penetrated the furthest and seemed to make contact with the large driver disk. Going in through the wire holes only reach the smaller upper disk. Given its' somewhat iffy connection (unknown at the time) to the large disk those points probably wouldn't have been useful in punching out the driver assembly. I also half submerged the head in boiling water for about 15-20 seconds. This wasn't so much to try to soften the glue/epoxy as to have the aluminum head expand faster than the PCB and crack the glue joint. Anyway, a sharp tap on the screwdriver and the driver popped loose.

As for the failure of the driver... the only thing my untrained eye could see was the "thingy" connected to one of the "half-moon" contacts on the flip side of the large driver disk had broken free (see red arrow in photo below). Maybe it was due to the fall, maybe the boiling water, maybe it was something else entirely. It's beyond me to fix it so on to a new driver an led.

Since this is my first go at this, any suggestions. The info in the forums (and others) is overwhelming. I was always happy with the original specs of the Quark AA2 - 180 lumens, 7 modes (especially moonlight), Cree XP-G R5, used daily/nightly and only had to re-charge batteries every 3-4 weeks. So I don't think I need the latest and greatest, but am open to suggestions (as long as I don't burn my fingers). C_k, you mentioned an MT-G2 and a "great driver". If you are still following this any suggestions for that driver. And, thanks again for your help.

Good effort mate, great work so far! My big fat sausage fingers would have bust something by now!

Depending on the dimensions of the driver, you could probably shoehorn in a driver board from Sofirn. They’re sold separately.

The SP10 is for an e-switch, so that’s out, but maybe the drivers for an SF11/’14/etc. might work, anything that uses a tailswitch.

Got it apart, so the nastiest bit is over’n’done-with.

If it’s 17mm, you can get a 1-mode boost driver (800mA) for 1V-3V from FT, too, if you’re not emotionally attached to multiple modes.

Thanks for the thoughts. I just noticed that Kaidomain appears to have a revised website up. A couple of multi-mode 17mm drivers listed (but no moonlight). Living in Nicaragua good quality AAs are hard to find and anything else forget it. Thinking about a single 14500 and dummy if someone I know is traveling this way and they can pack them in.

I’ve got some suggestions. Not sure this will work with your ambition.

Looks like the inductor came off. If its not mechanically broken you could re solder it back on. My guess is that wasn’t the source of the original failure but a result of disassembly. If you have a multimeter, you could test the inductor for an open connection. It should read very low resistance. If good, reinstall it. It doesn’t matter what direction you place it. Then comes the task of checking out other components. The most likely suspect is the switching mosfet. That is likely an SOT-23 size part. I’d have to have a good close picture of both boards so as to identify where it’s at.