HELP! Ultrafire WF-502B problem

[z_dynastes]

I have this Ultrafire WF-502B which I really like, light is very nice and like the quality of the flashlight. The problem is that sometimes the light goes by itself to a very low power mode (very faint). Turn it off and on again and it starts good again but it gets annoying as sometimes is very often, a couple of times every minute. Ive tried with fresh batteries and happens the same. Thank you!

 

[WraithFox]

UltraFire WF-502B 300 Lumen Flahslight (Having Problems)

Well firstly I must say that this is the most amazing compact flashlight I have ever used. I was simply amazed by how bright it was, it put the high beams on my truck to shame! Everything seemed to be perfect, That is until a few days later I started having the flashlight randomly dim when it was held at certain angles for a long time. Sometime, dimming gets so bad the light goes out..

After some experimenting, I have concluded that this mostly happens when the flashlight Is either pointing mostly up or mostly down for extended periods of time. When the light is held perfectly level, it eventually goes back to its original brightness. I looked around for a while and eventually found a single youtube comment of someone stating that they were having the same problem in a different light that uses the same battery. Both lights use the Lithium-Ion 18650 Protected batteries.

Has anyone else had this problem? I really hope its just a bad battery and nothing wrong with the circuitry of the light, I have simply fallen in love with this flashlight and really dont want anything to be wrong with it... :(

 

[^Gurthang]

Re: UltraFire WF-502B 300 Lumen Flahslight (Having Problems)

Welcome to CPF.

Please check the "Troubleshooting guide" sticky at the top of this forum thread list. I suspect that it's a loose clicky switch, simple fix. Good luck.

 

[Mike_TX]

Re: UltraFire WF-502B 300 Lumen Flahslight (Having Problems)

Agree with Gurthang - it's likely not your battery, but instead an issue with proper electrical contact. The clicky switch in th end cap is a likely culprit, and simple tightening is usually all it needs.

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[trooplewis]

Re: UltraFire WF-502B 300 Lumen Flahslight (Having Problems)

You will need a pair of fine-pointed tweezers to get into the two impressions/holes in the switch to fix it.
Or a nicer tool, like split ring pliers or needle nose pliers with fine tips. easy fix...

 

[WraithFox]

Im having the same problem! After taking it appart multiple times and reputting it back together, I am starting to believe the light has faulty circuitry. I know that the battery is good and the tail switch is good. The different modes all take place in the Emitters chip.

 

[^Gurthang]

Fox,

It is possible that you have an intermittent connection at the driver circuit. Again, the sticky "troubleshooting" thread at the head of this forum has how-to guides you will find helpful.

 

[jondotcom]

I'd buy a new drop in from dx, after first checking the tail switch and spraying some wd-40 in it (the switch).

 

[Mike_TX]

There is a small metal tab in the base of the 502B's tailcap - make certain it is in good contact with the spring. Otherwise you are not getting good electrical contact there. I've seen 501's and 502's with iffy contact at the tab and that caused intermittent problems. All it takes is to bend the tab a bit or capture it in the tight base coils of the spring.

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[EZO]

The recommended "troubleshooting guide" is the best place to look for a solution but certainly the first thing to try is cleaning the contacts. Make sure to clean the battery contacts along with those in the flashlight. If you don't have a proper solvent often a clean pencil eraser works great. This worked for a similar problem I had with an Ultrafire 501b and the problem never returned.

 

[shao.fu.tzer]

Buy a better light! Hehe.. you know that was coming...