First post... Ultrafire with intermittent problem. Help?

Hi to members!

I just signed up for this forum. I was modding incan lights in the early 80's just for fun. I have started getting the bug again.

I have a problem with 2 LED lights that I bought one year ago.:help:
I bought an Ultrafire C5 2xAA new on ebay, and also a different 3xAA long throw flashlight.

They both worked great for about 2 weeks, then got flakey, and now they are useless.

The problem with both is the emitters work very intermittently, and will not stay on.
They flicker, go dim, go bright, go off and on.

Both are 2 mode lights. On/off.
The Ultrafire is twist to on, the other has a tail switch.
I am able to get them lit for a while by unscrewing the threads of the tail or head, but then it goes dim or off again. There is no way to keep the lit or useful.

My efforts have been...
1. Add silver conductive grease to the threads to improve grounding. NO HELP
2. Clean off grease, and polish threads with a Dremmel wire brush. NO HELP.

OK, anyone know what the problem is? I am ready to toss them out if I can't fix them .:hairpull:



I have learned about DX from this site, and am tempted to buy a few lights for gifts, but I am afraid of problems like this shortly after giving them away.:thinking:

http://www.dealextreme.com/details.dx/sku.13442

http://www.dealextreme.com/details.dx/sku.14909

http://www.dealextreme.com/details.dx/sku.12325

Will this happen again?


Thank you for your ideas.

:welcome:
Sounds like you've tried the first usual suspect. Dirty contacts.
Second of course is check your cells and make sure they're fresh/ charged enough... sounds like you know enough to not make this mistake.
So that leaves us with another topic that is very often discussed around here...
Quit buying ultrafire, ebay and DX junk! It will keep happening with lights of such low quality.

Quality is always hit and miss with those, and your story is far, far, far too common around here. Could be just the usual poor soldering job and something came loose so check that if you can. But really you'll find very little sympathy on such issues. Sorry I can't be much more help than that.
But do hang out read up on some of the amazing lights that are available and learn about new modding possibilities on CPF. (and hide your wallet) The bug will bite hard.

My UltraFire lights seem very particular in wanting a fully charged battery. I assume you are using newer AW 18650's? But I have to agree the quality is poor in these lights. I would go with nothing lower than a Fenix level of quality light for a gift...unless you want to spend the big bucks for Surefire...