BB650 stopped working

My BB650 in my FF2 stopped working. At first it would light up for a second or two then turn off. It did this a few times so I put in a new (known good) battery. Now it doesn't work at all.

I bench tested the sandwich with a good battery and leads and it still won't work, so I know it's not a connection problem in the FF2 body/head somewhere.

Is there any procedure you can recommend for testing the sandwich and isolating the problem to see if I can fix it?

Thanks

There is not much you can do with the converter since it is epoxied into the sandwich, but you can test the emitter. Using test leads or wires, connect them to a battery (3 volt) and your emitter. Make sure you have the positive on the anode side of the LED (on a Luxeon the anode side will have a slot or hole in the tab). If the LED does not work then most likely the Badboy is also ruined since they do not have "open load protection".

Thanks, I just tested it and the LED is good.

Oddly (to me), using a continuity meter, I have continuity between the positive contact on the sandwich (the solder blob) and the negative contact (the upper surface that mates with the FF head) yet I have no continuity between the solder blob and the positive side of the LED. Is this normal?

I took a small soldering iron and refreshed the blob and the heated up the connections to the LED. Now it works again, but only at a fraction of full power, maybe a fifth or so. I'm guessing one of the connections inside must have come lose. I dropped the light on the tile a week or so ago, one of the solder connections inside might have broken....I don't know, I've never seen the inside of one nor built one before.

I guess I'll take a look over at the Shoppe for some new parts. Any suggestions? The LED is a TWOJ I swapped in a couple of years ago and I'm happy with it so far, unless I could put a Cree in the new one or something.

is it possible that when you do the swapping, the soldering is actually a cold joint? If that happens, then the BB practically running open (which is a no no) and burnt the sandwich altogether.
You mentioned that when you resoldered, it only turns on at fraction of power, which I would guess that the BB is actually in does not operate and only doing DD. This would confirm my earlier guess, but there might be a better (more positive) guess possible

The swapping was done 2 years ago and the light worked great up until last night when it stopped working, so my guess would be that that's not the problem.

I just "refreshed" the solder blob and LED connections a few minutes ago and now the light works, but not at full power. You might be right about DD, but I don't know enough about the sandwiches to say one way or the other.

Your description matches an open LED condition.

That will blow the BB circuit and when the LED is soldied back on it will then work in DD. The battery will still light the LED and it will be dim since you are now only applying 3V minus one diode drop.

A Nextgen, Madmax, GD converter board will all make a good sandwich for a replacement module.

-Wayne

Thanks.

Can I buy a sandwich without the LED from your shoppe and then just solder on my TWOJ? Or do I need to buy the individual components and assemble the sandwich, which is no big deal for me but I'd need to know what to buy and see a diagram or instructions. I'm assuming I can't just remove this converter board and put in another since there's epoxy holding the uppper and lower boards together (I think). Sorry for the dumb questions, this would be my first time assembling a sandwich.

Steve

I was just looking around the shoppe and I saw the GD500 you mentioned above. Can I use both primaries and rechargeable 123's with that board and have full output using either one? Would that be all I need to buy? I have a spare bare emitter board and 2 connectors that I picked up a couple of years ago and never did anything with. Would I need anything else?

Sorry if I'm asking questions that have already been answered elsewhere. I did a search but didn't really find what I need to know.

(EDIT....I found it )

as for the emitter option, you might try ask wayne to see if he is willing to solder the lux for you (you send the lux, he solders it to the sammich for you)
That way, it would practically eliminate the possibility of another open (cold solder joint) case, at least not in your part.

Even better, you should try to upgrade the current lux to some U bin, a cheaper one if you may.
As for your current BB, since it is seemingly dead, I would just short the butt plug (V+ in) with the + led in, and run it in DD from alkaline.
At J Vf, it would make a nice DD light

dat2zip said:

Your description matches an open LED condition.

That will blow the BB circuit and when the LED is soldied back on it will then work in DD. The battery will still light the LED and it will be dim since you are now only applying 3V minus one diode drop.

-Wayne

Click to expand...

How much is the diode drop? Is it worth me soldering a tiny jumper wire to short the blob with the LED + for now?
Thanks
Steve