Help fixing/replacing LED/Driver on knockoff Surefire

[viper726]

Hi all,
I have been crusin the forums for a little while now, reading and now i have some questions. Hope you can help.

I got this knockoff surefire (yea i know, but for $35 with batteries...) It takes 2 CR123 lithiums, and has a Lumileds Luxeon (TWAJW 0210609 2606LXHLLW3C is on the back of the star) LED/Star. It worked awesome for a few months, brighted LED flashlight ive ever used, good runtime, no issues. then the last 2 times i used it, for less then 10min at a time it got hot. very hot. I took it apart and the batteries were cool and the heatsink was warm, and i didnt see anything wrong. Then i took it with me for work, thru the airport xray machines twice and when i got home it was not a happy flashlight. fully charged batteries and the LED would be semi-bright for a split second after i click the switch then would only faintly glow. the driver is pretty much 2 1/2 watt resistors (cant see the ohms without cutting wires).
So i assume the LED died for some reason :mecry:, what would be the best way to replace it? i was thinking about a regulated driver as well but i dont think it would fit. how do i determine the optimum running Voltage of the LED, maybe they were over powering it and it died early?
i can take some pics of the assembly tonight if it would help.
Anything else i should try? or test?

thanks all

Jason

 

[Gunner12]

Would you mind buying a new light?

This driver should work(These would work too but I'm not sure you'll need four). While you're at it, buy a Seoul P4 LED to replace the Luxeon and double the output(Twice as efficient LED).

Shipping would take about a month.

How much space do you have in the light?

:welcome:

 

[viper726]

i might have to just buy a new one, but i dont really want to spend that much right before xmas.. plus it would be fun to try and mod this one a lil.

I dont have much room, i think if i got the driver i would have to take it off the pcb and try to minimize the size.

The center of the Heatsink that the star mounts to is hollow in the center, it would give me a 5mm diameter by 20mm long place to try to mount the driver. dunno if its possible..
but for $10 i can get 4 drivers to play with (break ) and a new LED. the LED is enough to get the light workin better then before.
here is a quick pic..

thanks for the welcome also! :wave:

 

[Gunner12]

How wide is the inner diameter(the bottom part look like it has more space)? If it is more then 16mm, the you won't need to trim the board.

Try connecting 2 AA batteries to the LED(Or anything 3v DC). If it doesn't light, you have a fried LED.

Don't forget thermal paste/epoxy for a good thermal path for the LED(DX also has some).

 

[viper726]

wow. now that is something i have never seen before. one of my CR123's is wacked. The polarity is reversed according to my multimeter??? how is that even possible. even weirder, when i try to power the led from it, it just barley flickers then goes out, but its still reading -3.7v (even when i properly orient the + and - ).

Until now i didnt know what the forward voltage of that LED was so i was afraid to test it directly, bypassing the resistors. so had always tested it with both batteries thru the resistors. it appears the LED is good when i test with just the good battery i never even thought that one could be dead, i just popped them on the charger and when it was green i assumed they were good.

think im still gonna get the Seoul and the drivers, at least to play with if anything my nitro car needs a good bright headlight!


The last 3 mm of the HS widens to just short of 13mm, but there is plastic insert that goes in there with a wire in the middle to contact the + of the battery. i have all kinds of thermal compound (artic silver and alumina) from past PC projects.

thanks for the help, sometimes its the simplest things
think im gonna get new batteries along with the drivers and led. maybe take some before and after shots to test my first LED flashlight mod! :naughty:

 

[viper726]

also... what would be the light output difference (if any) between the 3.6 and the 3.0v cr123's using the 3.6V~9V 800mA Regulated IC Circuit Board for Cree and SSC LEDs? or just straight resistors?

any benefit in runtime to getting the 3.0v 1000mah 17335 or the 3.6v 880mah 16340 ?

protected or not?



As you can see ive never bought rechargeable cr123's before. :naughty:

 

[Gunner12]

The output should be around 100+ lumens with the board and the Seoul LED(Presuming 2 batteries)

A 16340 is pretty much the same as the RCR123 battery. 3,0v ones have a resistor which make the battery much less efficient. The 17670 battery would give you a bit more runtime(The size of 2 CR123 batteries) but won't work too well with the board.

Buy protected. Then you won't have to worry about overcharge or overdischarge.

 

[viper726]

thanks for the help. I went ahead and got some ultrafires and the ultrafire charger that has dual charging channels, as well as the LED, and the 4 pack of drivers.
wonder how long until i get it

 

[Gunner12]

I'd say about a month.