Intermittent problems with Arc AAA?

[asdalton]

Have people had problems with any of their Arc AAA lights (recently purchased) not turning on? I recently sent one back to Arc for this reason. The replacement arrived yesterday, and it has the same problem, too. /ubbthreads/images/graemlins/frown.gif

 

[NeonLights]

I haven't had problems with any of mine, but I sold a new one to a friend a few months ago and he had quite a few problems with it. He emailed ARC and tried everything they recommended, and it still would fail to turn on one out of every 5 or 10 attempts. I'm not sure if he sent it back or just lives with it now, but there have been problems with a few lights from time to time, but the problems are very few and far between from what I can tell.

-Keith

 

[sublinear]

I gave two custom-engraved AAA's as Christmas gifts, and both had this intermittent problem. I didn't have the opportunity to exchange them, but the fact that they *both* had the problem made me suspect the latest batch might all be this way, due to a component change or something.

The problem was exactly like you described, every 5 or 10 times they just didn't come on.

 

[RazorMaxx]

My older black one has always done it. /ubbthreads/images/graemlins/mad.gif I would take it apart and clean the threads and it would work perfectly.......until I "needed" it. /ubbthreads/images/graemlins/mad.gif

 

[BobG]

I have a AAA standard that is about four months old and does the same thing. Turns on first try about 70% of the time. It has never failed to turn on with a second try, however, so it never really bothered me. It has the longitudinal lettering as oppossed to the circumferential lettering of my older AAA's but they are all premiums and have never, ever failed to light.

 

[paulr]

Problem may be with the negative battery terminal contact. It happens with mine when I use cheap flat-ended batteries. It doesn't happen when I use alkalines which have a button-like negative end.

 

[Rothrandir]

i've never had this problem in many of my aaa's /ubbthreads/images/graemlins/icon3.gif

it's sad to hear that it happens, but luckily (contrary to what it might seem like in topics like this), it's a very small minority.

i don't have a whole lot to suggest here...send back to peter? /ubbthreads/images/graemlins/crazy.gif

 

[paulr]

Roth, how many different kinds of batteries have you tried?

 

[Rothrandir]

i don't even know...

to be honest i haven't used a whole lot of batteries.
i can recall using some "osco" ones, and some energizers, but if i've used other ones, i can't remember what they were /ubbthreads/images/graemlins/icon3.gif

 

[Luff]

Of the five I bought before Christmas, all those from the December 19th production run had this defect. Returned one to place of purchase and am waiting on replacements from ARC for the other two.

If the new ones exhibit the same problem, back they'll go. ARC will make it right, but wish it wasn't happening at all.

 

[Flying Turtle]

I, too, have noticed the problem with "flat-ended" batteries that paulr mentioned. Fuji batts are kind of flat. Rayovacs seem okay.

 

[StevieRay]

I wish Peter would address this problem publicly via this forum.

 

[paulr]

I'd be happy to send some of the cheap batteries to Peter if he wants to test with them.

 

[brickbat]

While batteries may contribute to this problem for some users, there is definitely a failure mode that has nothing to do with the batteries. If it's like the 2 AAA's I had, it's not the battery, foam retainer, positive battery contact, negative battery contact, dirty threads, etc. I did some testing on mine - I soldered a small wire directly to the head's + contact and used a large aligator clip to connect to the threads for the negative. This gave me as good a connection to the power as I could imagine. I powered it from a regulated lab supply at 1.25Vdc and the problem persisted. About 10% of the time, I could apply power and it didn't light, or draw any current for that matter. Without a doubt, it was internal to the head.

The good news is that ARC's warranty service will take care of you. The bad part is that we'd rather not need it...

I too would like to hear about what Peter is finding out about the cause of this issue.

 

[paulr]

Brickbat, hmm, that sounds like a problem getting the oscillator started up. Did you try cranking up the bench supply to 1.5 volts, and what happened if you did?

 

[Gransee]

SteveRay, there are previous threads on this. Right now I am behind on my CPF messages. My apologies.

Here's an update:

We have made several revisions to our design to reduce the instance of this occuring. Previous revisions concentrated on the how the PCB was grounded. But the problem persisted even though we have a good grounding system now.

Personally, I think the most recent problem is caused by a odd power supply stall. The switch on the chip gets stuck in the on position. As a result, it continues to draw power but does not make enough to fire the LED since it is not switching. Our circuit has not changed in quite a while so I think the chips we are using have changed in some small way. The fix I came up with involves adding another part to make the circuit more tolerant of chip variations.

It is possible it also gets stuck in the off posistion, but I have yet to observe that.

The chip manufacturer is not to blame because their parts meet the specification they published. It is my fault for using their chip in such a small housing which forces me to use minimal parts. However, their part it the best for our application in my opinion. Fortunately, I can add yet another part (with difficulty and extra expense) into the housing without changing the size of the Arc-AAA. I will not increase the price of the AAA or AA because of this. My contract with you is to produce a unit that works.

One of the reasons we have been out of the AAA and AA lately is because I pulled all of our stock (very expensive). Testing of the new design so far seems to fix every instance of the problem we observed. This was done by taking unglued electronic assemblies and placing them in a head and turning the light on an off until it failed to start. Sometimes this would take dozens of turns. We then took that board out, made a change and repeated the test. In all cases, the units then worked as they should without stalls. This is a simplfied description since it took trial and error to find the correct part value that would cause the unit to start each time. Like I said, it is an odd problem in the first place.

Unfortunately, I cannot go back and fix any units that has been fully assembled because the heads are glued. Taking them apart destroys more than you save. I will probably liquidate them on ebay someday.

Any rate, I have been working variations to this problem for about 6 months. I haven't always been able to devote as much time to is as I would like because of the Arc4 and other obligations (I really need to hire another engineer). But I have a fix that has been performing well in our tests. We have gone ahead and put it to manufacturing and those have been shipping now for about 2 weeks. So far, they seem to continue to work fine once they get in the customer's hands.

I think the units we shipped in December are the bulk of the problem units. If you have one that is acting up, please let us replace it with the new design.

And yes, I would prefer we fixed every problem before it went out the door. The reason the problem units passed QC is that we turned each unit on and off only about 4-5 times before it shipped. Now we take 10 from each batch, put them in the freezer, then in hot water and then turn them on and off for 50 cycles (by hand) and note what percentage fail to start even once. So far that test has produced 100% light up on all of the new units tested. There is a possibility that a similiar version of this problem may appear or that a defective unit may escape the new tests but I think we have at least significantly improved reliability.

Peter

 

[Rothrandir]

[ QUOTE ]
Gransee said:
...(I really need to hire another engineer)...

[/ QUOTE ]

well i'm not "qualified" per se, but i'm certainly willing and unemployed! /ubbthreads/images/graemlins/grin.gif

at any rate, i'm glad to hear that thigs are workin [even] better now! /ubbthreads/images/graemlins/grin.gif

 

[Carpe Diem]

As usual...

Good job, Peter...
Good job. /ubbthreads/images/graemlins/thumbsup.gif

Thank you! /ubbthreads/images/graemlins/smile.gif

 

[paulr]

Thanks Peter.

 

[03lab]

Hmm, just got my Arc AAA yesterday but only read about this problem now. So I tried turning it on about 50 times and surely enough it won't come on with a 15 % chance. /ubbthreads/images/graemlins/rolleyes.gif

Well, I guess sending it back to the US is going to be too expensive for a light that works 85% of the time. But now I wish I had bought one of the defective units for a lot less $ from the upcoming Ebay liquidation instead. /ubbthreads/images/graemlins/icon23.gif