Dorcy 3AAA mod - help request

[jimi]

I recently found an old Dorcy 3AAA light that I haven't used for a couple of years. It's the same light from these threads.
I think the board is busted, as after I put in a new set of batteries, the light turns on and stays on (the button doesn't work). I took it apart and there doesn't seem to be anything wrong with the actual button, which is why I'm guessing the circuit got messed up somehow.

My question is this: What can I do with it now? I'm completely new to modding flashlights but this seems like a good place to start. Any suggestions on boards or bulbs that I can put in here (preferably from DX as I need to order some things from there anyway)? And how can I fix the switch?
I'd like to keep the 3AAA power source as I've already got lots of rechargeables lying around.
Thanks for the help!

 

[Gunner12]

Does the clickie feel fine when you try to click it?

IIRC 3AAA lights like the Dorcy lack any real circuitry. It's probably just a resistor.

You can try to fit a different switch from DX. You can swap the LED for a current gen one, the Seoul P4 probably works best. You can add a multimode driver.

The LED swap would probably be one of the easier ones.

:welcome:

 

[jimi]

Thanks Gunner12.
The clickie feels fine, which is why I though it might be something else. I've taken some pictures of the actual board here, but don't really know what anything is, besides the resistor.



Ideally, I'd like to get the clickie fixed for just a simple on/off. The light originally had an on/strobe/off, which is what the extra components are for (I'm guessing). How could I go about doing that?

After that, I'd like to put in a new LED, most likely this one from your suggestion. From what I can tell, this is the easier task and would just be a simple switch with the current star.

I've got limited soldering experience, but am willing to learn, especially since the light is pretty useless if I can't turn it on or off. What would I need to fix this light and where would I be able to find it (preferably in Canada I guess due to shipping costs). Are there any basic soldering guides out there that I could take a look at?

I figure once I get all this figured out, I can take the old star and put it in my Rayovac headlamp to replace the incandescent bulb. I'm beginning to see how modding lights can become addictive...

Thanks for the help...it's really appreciated!

Does the clickie feel fine when you try to click it?

IIRC 3AAA lights like the Dorcy lack any real circuitry. It's probably just a resistor.

You can try to fit a different switch from DX. You can swap the LED for a current gen one, the Seoul P4 probably works best. You can add a multimode driver.

The LED swap would probably be one of the easier ones.

:welcome:

 

[Gunner12]

Now I see, it's more complex then I first thought.

I don't have much electrical experience so I can't help you with the driver(the circuit). You might be able to take it out and place a fitting switch in it and somehow make it work. Like mount the switch to a board and wiring one end to contact the batteries and the other end to the + of the LED. Sorry if that was confusing.

High power LEDs need heatsinking when running at higher currents. They also need the right voltage unless you have the right driver for the LED. What batteries does your headlamp run on?

DX has shipping in their price but they take a while to get the product to you.

 

[PhotonWrangler]

zombie thread...

I just had a 3AAA Dorcy (same model as mentioned here) fail in the same manner - it won't turn off.

Disassembled down to the driver board where there is a switch, one driver transistor, a few resistors and caps and a chip-on-board "blob" driver IC. The physical switch tested ok. The transistor is marked 014M and the silkscreen around the leads says S, D and G which makes it a FET, something I can't easily test with a VOM, at least not while it's in circuit. It might be an IRFD-014M, an N-channel power mosfet. If this is the part that failed, it would have failed with a short from source to drain, although I suspect it's not the transistor.

My primary suspect is the driver chip. If this is the case, the electronics are essentially toast. I could bypass it with and wire the switch through a resistor but I'm wondering if it's worth the trouble.