May be forced to mod P60 Drop-in :(...

Hi,

That emitter board definitely does NOT want to be removed from the pill.

I unsoldered the - lead from the emitter board, and tested, and got no light, so I started aggressively trying to extract the emitter board, but it just won’t come out. It looks like they put that white stuff over the entire bottom surface and it’s basically glued solid to the pill :(. I’ve even taken a small screwdriver and tried to pry it off of the pill, but it ain’t moving at all :(…

Yeah, I wish they wouldn’t use that stuff. It’s not necessary because the reflector holds the emitter down. The adhesive is not that strong, but the flat surfaces give a lot of surface tension that is difficult to break sometimes. Once that surface tension starts to break at any spot, it will come off easy. Try pry upward with a strong tool like I screw driver that you mentioned. I find holding lighter, continuous pressure does less damage than going full out Arnold.

I find that alcohol works good for cleaning up the residue. Maybe it can help loosen the bond.

Chances are you won’t hurt the pill beyond repair. But if you do, it’s only a buck for a new pill:

https://www.fasttech.com/product/1164600

https://www.fasttech.com/products/1616/10002799/1208606-driver-pillar-for-flashlight-diy

Hi,

I’ve put it in the freezer last night/this morning. Will try more prying later :)…

Edit: Not a good “welcome” to the “modding world” :)!!

Edit 1: Just took it out of freezer and did a bit more prying, and it finally popped out :)!! The edges of the pill are bent a little in various places now. Is that going to be a problem?

Naw, it won’t be. If any of the protrusions get in the way of anything, just file it down. You do need a good flat service for your emitter base for heat transfer. I imagine you probably know a lot of the stuff I write here. So please forgive me if I am saying basic things you already know.

Welcome to the world of modding. It usually isn’t as pretty as most postings you see in the threads.

Now that I have everything apart, and seem to have confirmed that the emitter is dead:

- How can I confirm that the driver is working? Can I just connect an 18650 to that, and measure the open circuit voltage of the black/red leads?

- Which emitter+emitter PCB to get?

- Also, I don’t have a caliper, so what size? Seems like 16mm is the smallest, so can I go with that, even if it might be smaller than the original?

Jim

I wouldn’t get rid of the emitter yet, I’d still bet on the driver being the broken component.

If you want to be sure the LED is broken then you should take a partially discharged li-ion (probably down below 3.7v to be safer) or a lifepo4, primary cr123 etc (anything around 3v) and connect it directly to the LED with a wire on each end of the cell and each LED contact with +ve and -ve matching up.

If it doesn’t light up after that then I take it back and the LED is probably dead :wink:

Hi,

I know that others have suggested that, but I’ve hesitated doing it.

Theoretically, with the emitter/diode in forward-biased, it becomes a short, so, without a series resistor, won’t that put too much current through the emitter (like “infinity”)?

So I wanted to summarize what I had to do so far to disassemble this drop-in, in case anyone has to do this later:

1) The driver is soldered to the pill at the edge at two points, so those 2 solder joints have to be broken or desoldered. In my case, I used a small, sharp pocket knife, and cut through the joint, slowly. If you do this, be careful, because your fingers are going to be close to the blade!

2) The emitter PCB is covered with a black insulation disc. That disc can be removed by prying around the edge. It popped off fairly easily, exposing the actual emitter PCB.

3) The emitter PCB is stuck to the pill using some kind of white substance. What I did per suggestions here was to put the whole pill, etc. into the freezer overnight. Then, the next morning, I used a small, flat-bladed screwdriver the fit between the edge of the emitter PCB and the edge of the pill, and pried, moving the screwdriver around the perimeter and prying at a couple of places. The emitter PCB eventually popped out.

Do yourself a favor and replace that black insulator with one of these:

https://www.fasttech.com/product/1182004

They are my favorite xml insulator/centering bushing. The picture of it is upside down. They snap on the the emitter’s pcb and do a great job of properly positioning most reflectors.

EDIT: Oh, get some thermal paste (not adhesive) if you haven’t already. The paste doesn’t harden. Makes future changes so much more pleasant. You want 16mm led stars and 17mm drivers.

EDIT2: I haven’t shopped for emitters in a while. My last purchase was from Mouser for XML2 T6 NW (I think 3C tint). Man, I love that emitter. Hopefully, someone here can give you some direction.

I imagine the MCU is fried on your driver. You could test like you said. A better test would be to try with another led. That way you could see if it works under load with all the modes.

Direct connecting to a battery won’t hurt your led if you just quickly touch for a second. Believe me, if it’s good, that is all you will need to know. Try not to look directly at the led when you do it. I like to wear sun glasses when I test mine that way.

Earlier it was suggested to use a somewhat used Li-Ion battery, which would be, say ~3.0V. Would an Nimh battery, say ~1.2V also work? Or not?

I use 2 nimh. You don’t need 3 volts to light up the led, but you probably need more than 2v.

The XM-Ls forward voltage is around 3.0v rising as current increases, li-ion nominal is 3.7v dropping as current draw rises, so they balance out at a reasonable amount in direct drive. As long as you use a partially discharged cell, it shouldn’t be much more than the 3 amp max rating and is probably less.

The only worry is that you could fry the emitter with heat if it isn’t attached to any heatsink, but you only need to touch the wires in contact for a second to test it so that shouldn’t be an issue really.

For emitter:

This:

http://www.fasttech.com/products/1609/10001903/1224000-cree-xm-l-t6-4c-4300-4500k-943-lumen-white-led-emi

or:

http://www.fasttech.com/products/1609/10003889/1277804-cree-xm-l2-t6-1c-10w-6500k-1052lm-led-emitter

or:

http://www.fasttech.com/products/1609/10003889/1277805-cree-xm-l2-t6-1b-10w-7000k-1052lm-led-emitter

??

For thermal paste:

http://www.fasttech.com/products/1506/10002067/1148100-zp-silicone-heatsink-thermal-compound

??

ImA4Wheelr and RedForest,

Ok, I have a 18650 @ 3.09v, will try that and thanks for the info.

I have that T6 4C coming (if HK post ever picks the package up off the floor where it fell off the conveyor and gets it shipped!!!). You could also try the T6 3C. Both neutral, but the 4C should be slightly more yellowish.

I use Fujik compound or Fujik glue depending on my purpose. The compound stays pliable, the glue hardens . . . like glue :) . I've heard that you can mix them 50% / 50% for a compound that is a bit more sticky.

Oh, and I've used a LifePO4 fully charged to test an LED (just quickly tapping). As stated above, do not look directly at it!

-Garry

Just tried with the battery, and got no light, so, at LEAST, the emitter is dead.

The product is great. But just a heads up to beginners who buy them. Make sure that the wires does not short, or can not easily make a short circuit to the reflector. If your wires are thick, or your soldering point is a bit high. Or the wire is not functioning as isolation, you can get a short circuit.

These are very safe to use, but then you have to do the centering yourself.
http://www.fasttech.com/products/0/10001923/1138102-pet-insulation-gaskets-for-cree-xm-l-t6-led-emitte

There are many ways to do things. But if you use thermal compound (silicone glue). Then you can first use one of the centering insulation thingies ImA4Wheelr linked too. Then change it out with one of those plastic insulators that cover the wires for maximum safety (after it has set, and is perfectly centered).
These days I prefer to not use anything with glue under the emitter if I can avoid it and I have an reflector pressing the emitter down. I use high quality CPU paste instead. Sometimes I use Fujick around the emitter just to hold in in place (but good thermal paste under it). Not only is it better for getting the heat away, but changing the emitter is super easy too.

Theory about why emitter died?

I’m not familiar with the driver designs or the design for this one, but maybe the driver is designed to just pass the incoming voltage through to the emitter if the incoming voltage is, say, > 4.2V?

In my (unfortunate) case, I had 2x18650, so about 7.4V - 8.4V, which, from earlier post is > than the emitter maximum voltage, so maybe that, plus the theoretical driver behavior (pass voltage through to emitter) would kill the emitter?