Drastic Arc AAA brightness changes due to temperature?

I've had my Arc AAA since mid January, and I love the light, it's around my neck 24/7, sometimes off sleeping if I roll over on it and take it off. I don't want to do without it, it's constantly coming in very handy since it's right there all the time.

But it's driving me insane at the same time! About two months ago it started flickering and acting weird, I changed batteries, fiddled, cleaned, wiped, erased, and suddenly it was fine. I had even emailed Arc asking what I could do, they responded pretty fast, but I had gotten it working. Since then, it's done this at least every two weeks or so, I'll have to clean and wipe and fiddle and get all confused about what's going on.

Then I started noticing in the shower the light wouldn't come on, or it would come on SO DIM you could *just* make out the emitter, and if I left it on by the time I toweled off, brushed hair and teeth, it'd be back on. Later I noticed as I was under a heat vent it did the same thing, went to use it, it was fairly warm (nowhere near uncomfortable to hold) and it was extremely weak. At that point, I got curious, tossed it in the freezer, and in about 20 seconds it was back to normal. I let it warm back up slowly again, then put it near the heat again, repeated, and it did the same.

When it's warm/hot it's very, very weak, when it's cooled back off the light is normal.

That was then... Now the light is *always* in moon mode, sometimes it'll flicker from moon to sun back and forth a little, sometimes winding up in either mode. Heat still makes it less bright, but cooling it doesn't necessarily make it brighter. I don't know *what* to think, I'm considering that perhaps the regulator board is just defective.

Just to clairify some things, the heat transitions aren't large temperature transitions, nor are they extended exposure, so the battery itself is unlikely to be changing temperature very much, ie: I'm not melting it, or trying to make a superconductor out of it. I've wiped and cleaned every possible lubrication off of the light, thinking perhaps the spray-on teflon stuff I have (Triflow) was insulating, but I don't think that's the case anymore, I've wiped and wiped. I've used an eraser on the bottom and top contact, reflowed the button contact with an iron (doesn't take much to do, I was kinda surprized!), and of course replaced the battery with brand new ones, I have a 8 pack of brand new AAA's, I've tried several of it, plus I've bought another set of four AAA's of another brand.

I am about to print out a return slip right now (exchange of course; I don't want rid of it! but I wanted to post this as well, to see if Peter or anyone has any ideas? The light has never been dropped (probably not so much more than onto carpet from a few feet!) and I've never used anything except regular AAA's in it, no lithiums, etc.. Never hooked anything up to it, etc.

The sponge retainer looks like crap where I had to take it off to reflow the button, but other than that (and the slight silvering around the lanyard ring hole where I dangle the light from my neck) the light is in perfect condition.

Maybe someone will have a guess at what went wrong, I hope I just got a dud, it'd stink if I got a replacement and that one did the same thing three months down the road, first because I gave up my first one, and two because I'd be left wondering again

Cheers.

After you have cleaned the arc, try sticking a piece of aluminium foil at the bottom of the contact point. I doubt it is the temperature change that cause the flicker.

I have used this method to eliminate some flicker in my arcs. So far so good. Sometime you may need to readjust the foil in case it come loose. Try it.

Pardon me, but you shower with it? I know that it is claimed to be water resistant, but still, I won't shower with something that is not 100% dive proof.

Although you are not immersing the light to the depths that would definitely allow water to penetrate due to pressure (a few feet for the Arc-AAA), the trouble is that the same amount of pressure can sometimes be achieved by the showerhead. The stream of water from the showerhead can force its way in to the electronics of the unit. That is why I will never expose any equipment to water unless it is dive rated. Even then, I want to be able to check all the gaskets and o-rings periodically.

However, that is merely an aside, since upon further reflection, the electronics of the Arc-AAA are potted in epoxy, so I can't quite imagine what might be wrong.

It certainly would be good for Peter Gransee to get hold of it to check what went wrong.

Yes Khaytsus, please send it back.

These symptoms are consistent with a problem we have identified awhile back and are fixing with an upcoming design improvement (see my Arc forum notes on this bbs).

Due to normal thermal expansion in the epoxy, the PCB slowly works its way from the housing. This causes the PCB to loose its ground contact. Symptons include flickering, complete failure, twist on light variations and general intermittant operation.

A quick test proves the observed symptoms are being caused by this particular fault: Shorting the case against the backside PCB ring will cause the light to work normally again. In some cases, I have used a drop of solder to achieve this, but it is temporary because solder does not stick to aluminum very well. If the short does not improve operation, then the problem is poor battery contact or the battery. A large percentange of the units returned under warranty have this grounding problem though.

We have a fix in the works. It include a design change to the head and a new tool assembly for the production line. It has already been ordered 2 weeks ago. As always, I will keep you posted on improvements to each of our products.

Peter Gransee

Hmmm... So somewhere at Arc central there is a box of returned AAA lights. Put a cap on the barrels and you'd have some great spare battery carriers! Obviously not worth tooling up production for this, but it would be great to find a cap from something that would fit and put these back into the field. I enjoy giving a good home to orphan lights!

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Steelwolf:
The stream of water from the showerhead can force its way in to the electronics of the unit. <HR></BLOCKQUOTE>

No need to worry about the electronics getting wet. Can't happen. The head is completely sealed. The worst that can happen is that you get the battery compartment wet. And a while back we proved that even a wet battery compartment isn't really a problem (Peter and I both filled a battery compartment with tap water, then screwed the thing back together. After forcing the excess water out past the O-ring, the things seemingly functioned perfectly).

I don't shower with mine, but I know lots of folks do, and haven't yet heard of a problem. Heck, I've got one around here somewhere that was flushed in a toilet, then went through an entire wash cycle with the laundry. All that happened to the light is that it got cleaner

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by RevJim:
Hmmm... So somewhere at Arc central there is a box of returned AAA lights. Put a cap on the barrels and you'd have some great spare battery carriers! <HR></BLOCKQUOTE>

Or little indestructable pill bottles for wear around the neck...