My A2 incand beasm magicially has now 2 brighntess modes

[ma tumba]

My A2 incand beam magicially has now 2 brighntess modes!!

I have no idea what has happened to my light, but today I found this: when I press the switch half way the LEDs switch on, then when I press the switch further 1/4 the incand bulb is switched on very much underdriven and only after additional 1/4 press the bulb fires all the way up to its normal full brightness. And this how my light now works every time I switch it on..

Is it going to die soon, or Santa installed a magic driver when I was asleep?

 

[Minimoog]

My A2 incand beam magicially has now 2 brighntess modes!!

I have no idea what has happened to my light, but today I found this: when I press the switch half way the LEDs switch on, then when I press the switch further 1/4 the incand bulb is switched on very much underdriven and only after additional 1/4 press the bulb fires all the way up to its normal full brightness. And this how my light now works every time I switch it on..

Is it going to die soon, or Santa installed a magic driver when I was asleep?

That is a sign of bad contacts in the tailcap - which affected quite a few A2's. It also happens when the batteries are near depletion. It is caused by the regulator not being able to keep the voltage up.

 

[ma tumba]

Rather not. Tested the CR2 batts with a ZTE pulse load tester, both are at 100% capacity. Tried the tail cap from another A2, even worse, the bulb never gets to normal brightness, goes only into undersriven "mode"

 

[m4a1usr]

Is it going to die soon, or Santa installed a magic driver when I was asleep?

LOL! I hear you. Sometimes I get that as well from a specific light. Unexplainable behavior that makes me wonder if photon gremlins are busy at work. But seriously I guess the question that should be asked are you using one of Tad's Incan adapters or are you using the MA02?

 

[ma tumba]

But seriously I guess the question that should be asked are you using one of Tad's Incan adapters or are you using the MA02?

Yes, this proved to be a good point. I used an FM Strion kit and I have another one, with a fresher bulb. So when I replaced the pill I could not reproduce the magic anymore. Put back the old pill and was able to get to that underdriven mode, again. Have no idea what is the difference though.

 

[ampdude]

Normally that means the batteries are too weak to run the incan lamp at full brightness. Some weirdness of the A2 circuitry in the tailcap causes it to run at low mode when fully turned on with nearly dead batteries. Try a fresh set of batteries. If this doesn't fix the problem, the tailcap might be funky. I've never seen an A2 that went into low incan mode with good batteries. There is a low incan brightness mode most A2's go into when the battery has just about kicked the bucket.

 

[chillinn]

I've never seen an A2 that went into low incan mode with good batteries.

​

 

[m4a1usr]

Rather not. Tested the CR2 batts with a ZTE pulse load tester, both are at 100% capacity. Tried the tail cap from another A2, even worse, the bulb never gets to normal brightness, goes only into undersriven "mode"

Yeah I'm not surprised hearing about that performance issue when switching tailcaps. I noticed some years back with my own A2's and it was later confirmed when reading thru the "Surefire A2 thread index" thread that there is a critical OAL for A2 tailcaps. One should not go about swapping tailcap's between the various gen's and expect it to work without issues. I trimmed down a spare Z62 just to ensure I could swap it between the various gen's for trouble shooting function issues. It doesn't need much taken off. I think I went approx. .020 if memory serves correctly. Which isn't a whole lot.

Unfortunately I discovered after reading the Z62 disassembly thread I saw you can simply install a small washer behind the resistor/connection board that allows for a shorter OAL internal length and doesn't require the outer shell to be trimmed down. Oh well. Live and learn.

 

[chillinn]

My reading comprehension is not the best. Sometimes, it takes a few readings for things to click, so I have returned many times to moderator js' venerable post praising the virtues of the The SF A2, rediscovered the paragraph quoted below, then remembered this post. More or less, it is in greater detail to, but still along the lines of what Minimoog suggested above:

And for those of you who have often wondered what is going on when your A2 appears to have three levels (LED, low incan, high incan) depending on how the switch is pushed or on the luck of the draw, here is what is going on: there is some extra resistance in the circuit. (Assuming you have fresh full batteries installed, of course--low batteries will exhibit this low incan mode even if all contacts are clean and everything is in working order) The extra resistance could be due to contact resistance in the LOTC floating contacts or in the battery stack or somewhere else. Or due to a broken spring contact. But somewhere there is extra resistance—just small enough so that the LVR sees enough voltage to allow it to turn on but too much to keep it on. So it turns on and starts to draw high current through the lamp, which causes a larger voltage drop across the switch and contact resistance, which lowers the LVR input voltage, which causes it to turn off; and the same thing happens over and over again. Sometimes you push hard enough, or the position of the floating LOTC contact on the end of the body tube is such that there is a small enough resistance to run the incan in regulation. But other times, there is too much resistance, and you put the LVR into an equivocating state of confusion about whether it should be on or off, resulting in a sort of in-between state, and thus the so-called "low-incan" level. If you remove the switch and simply short circuit the battery stack negative to the body tube, I bet you will find (in these situations) that it works fine. This indicates the need to clean the contacts inside the switch with a soft cotton pipe cleaner, and the butt end of the body of the light with a cloth or paper towel.

 

[ma tumba]

chillin: you have been providing loads of valuable information these days, thanks a lot! I have to say that my current interest are very much in line with yours so I follow your posts with great interest!

 

[chillinn]

I have had more time on my hands lately and new high quality incan flashlights that have been exciting me to mania (as a stabilizer, the effects of Lithium have been recognized for millenia, but it destroys me taken orally, so I prefer to consume it ocularly; a Li-ion flashlight is merely another delivery vehicle for good medicine). I have been concerned that I may be getting under the skin of the long time regular, restrained and tempered CPF users that kindly oversee the information posted and filter it for accuracy for us all, so I appreciate it... that at least one member hasn't added me to their ignore list... yet. These periods of my greater activity will fluctuate, and I expect my posting activity to diminish sooner or later, though my lurking will remain steady.