Arc 4+ erractic behaviour

So this was weird. Lastnight I reached for my Arc4+ first run #0817 and it wouldn't turn on. No problem. Thought maybe I hit the switch by accident and left it on. Change the battery and it still woudn't light up. Oh poop. /ubbthreads/images/graemlins/icon15.gif

Well I change the batter again, but this time with a R123. The light starts to flash like it has strobe mode...pretty cool I thought. Until it wouldn't stop blinking even when I hit the button it would just stop blinking but start again. The sequence I got was:

- - - --- - - - --- ----------

Well I checked all my batteries and they were all fresh. So I start the painful reset of the light. See I disable RFS since I found no use for it whatsoever. I push the switch down in the head for like a minute and that worked. My light works like normal again now.

When my light did this my mode was:
RFS off
locator on
brightness levels on default setting
R123 battery (full charge, non-protected cell)

Anyone ever experience a problem like this before? I use this light everyday and this is the first time. However I have noticed that the locator keeps turning itself off.

I've had some erratic behavior where my light turns ON for no apparent reason and will not turn off again, not in strobe mode however. I got a lot of good insight when I posted my question so I anticipate at least one other person has had some issues....

Hello Elmie. It appears #817 has a pretty good LED in it. Was the strobe dim or bright? If it is towards the dim end of the scale it sounds like a low Vf flash visible because of the higher voltage (4.2v) of the R123. This routine should be off when the RFS is off, but you might check it anyways. If you go back to the 3volt cells, the flashing becomes too dim to easily see. Although, you have good current draw/output numbers due to your efficient LED, the downside is the flashing with higher voltage cells. New software (rev3) can fix this but it is unavailable at this time.

I see the real problem being the front switch not triggering when you pressed the button. This is probably due to a loose mechanism. You can test this by powering the head from a power supply to factor out the battery and tail mechanism.

You said the light stopped strobing when you pressed the button but then resumed. How quickly did it resume? The light could have been loosing electrical contact and rebooting between the strobes. I would check the tail mechanism to make sure it is assembled correctly and the spring is inside the basket.

Another thing, you seemed to indicate the light is no longer strobing even though you still have the R123 cell in place. It should still be strobing. The brightness is dependent on how sensitive your LED is, tolerances of the circuit and the cell voltage. Try recharging the cell, put it back in the light and look at it in a dark room.

Every problem has a logical explanation. I'll be here if you want to take this one step at a time. I would check the light again with a fresh cell, check the head without the pack (if you have a power supply, or use a battery holder and some wire, check the rear tail assembly to make sure it is properly assembled, esp the spring in the basket.

Peter

"Better, not bitter"

Hi Peter,

Thanks for coming a board and helping out. I'll conduct those tests when I get home later tonight. I've been using the R123 in the light for the past 2 months and this was the first time it acted like that. The light has just behaved the same way this morning. So once again I had to manually reset the light and is working fine again.

As for the strobbing. It flashes quite dim. While it is flashing and I hit the button it will stop for about a second and than start up again(while holding down the button). I have checked the tail end of the power pack and all seems well.
The other thing I noticed was that if I have locator on and RFS on. The light will out of no where stop flashing the locator and the RFS than cycles. So I'm guessing the light for some reason resetted itself(light was laying down on desk when this happend).

Once again, thanks for the help Peter.

Elmie,

There are only two conditions under which the light will "flash" when it is turned off. The first one - RFS - can be ruled out since the feature was turned off. The "flash" caused by RFS is normally very faint and most people never notice it - and is generally not affected by the type of battery used, but is affected by cold temperatures.

The other "flash" is the locator flash - which you indicated was turned on - and is the likely culprit. This flash is set to brightness level 16. The locator flash normally flashes about every 3 seconds.

The locator flash can become erratic if there is an intermittent connection in the circuit. Depending on where the intermittent connection is, the time between flashes becomes erratically long or erratically short. A hard failure produces no flashing or continuous rapid flashing, respectively. It is theoretically possible to have both failures at the same time, but this is not very likely. In your case, it sounds like the time between flashes has become erratically short. This means there is an intermittent connection or failure involving a single part on the circuit board. Because the circuit board is encapsulated in epoxy, this problem cannot be fixed.

There were many light failures involving that circuit due to improper circuit board assembly. In fact, I have one sitting here that has exactly the same symptoms - erratic rapid flashing. My other Arc4 has exactly the opposite problem - erratic long time between flashes. When the circuit boards are properly assembled, they are very reliable.

The battery you are using will not have any significant effect on this behavior. The problem is not caused or aggravated by using the rechargeable 123 batteries.

So that covers your first problem - the strobing - and is caused by a circuit board problem and cannot be fixed. On to the second problem.

When the light is strobing, two things can happen when the button is pushed. Either the button responds normally or the light comes on to a very dim brightness - much dimmer than level 16 and the button is otherwise ignored. The latter is a bug. Note that in both cases, the light stays on (assuming momentary mode here) until the switch is released.

Now you said that if you held down the button for a while, the light would resume strobing after a second. From your statement, I am assuming the light did not come on to the normal brightness for that second - and thus the latter case above would hold. However, the only way for the strobing to continue while the button is still down is for the button circuit to think that the button has been released.

In your third problem, you mentioned the light would reset itself when just sitting there - which could be related to the second problem. Go back to HesNot's problem a few weeks ago where the switch was being affected by residual flux becoming conductive with humidity. As it turns out, on the same surface are programming pins. With the proper conductivity between pins, it is possible to get both symptoms. Luckily, this can be fixed by properly cleaning the top of the circuit board - Cy can help you on this one. Note that there might be something else wrong, but this is the most likely cause.

There is nothing in your problem reports to indicate you are having battery contact problems or that your button assembly is having problems. All of your problems appear to be incorrect circuit board assembly problems - one of which cannot be fixed. But fixing the other two will provide you with a working flashlight that is only missing two features - RFS and the locator flash. Leave both turned off because they rely on the defective circuit for proper operation.

Henry.

You are welcome Elmie. Please let me know what you find.

Peter

Ok I have tried all the above suggestions from both Peter and Henry. Thank you both for trying to help out.
I checked everthing again. From head to tail. Tried a power supply on the head and it worked intermittent. So I ended up using contact spray cleaner and sprayed the inside of the head , cleaned the all the threads that are on the head and tail pack. Everything seems to be working fine now. I guess somehow I wasn't getting a good ground or positve contact.

I did notice that when i was using the contact cleaner that there was alot of black residue from inside the head. I guess that would be contamination from the aluminum oxidizing.

I'll let you guys know tomorrow if the light survived a full day without incidence. /ubbthreads/images/graemlins/wink.gif

Ok the light is still giving me the same problems. I have tried cleaning all the contacts and adjusted the switch in the head. My light still keeps flickering after awhile. I can't stop this until I try to reset it and even than it is almost impossible to reset. I hit the switch while the battery is out to reset the light back to factory settings.

I don't understand why the light would start acting up after using it for 10 months. It worked fine before. And I have never dropped it either! /ubbthreads/images/graemlins/icon23.gif

It is so much easier to diagnose a light when it right in front of you. /ubbthreads/images/graemlins/smile.gif When the input voltage from the battery falls below about 1.8 volts, the light can enter a mode where it flashes on an off. This usally only happens with a very dead battery. Normally, when the voltage gets close to that point the light toggles down a level which then causes the voltage to recover. It is conceivable that the contacts could be so dirty as to cause a sizeable voltage drop even with fresh cells. Some of the earlier software revisions where more sensitive to this if you remember. #847 has the newer software.

It is important to get a baseline behavior from the unit. This means to make sure you have a clean contact with the power supply. The reason for powering the unit without the battery pack and rear button mechanism is to remove them as a factor.

Sure, there is a possibility you are out of luck but I would feel better if we could rule out some simple causes first. You may have already tested it to your satisfaction but I am not clear on how good of a contact you are making with the head.

Of course I saw units that had defects in the PCB. Most were caught before they went out. Usually it was a 'tombstoned' capacitor that would cause the findme beacon to not work. After making quite a few of these lights, you start to see patterns in how they fail and what the fixes are. The problem you are experiencing could be completely novel, but experience cautions me against coming to that conclusion too quickly. I tend to think it is more of what I have seen in the past.

If you will pay the shipping costs (to and from), I will look at the light. It may not be fixable, but you never know. Normally I would send you to one of the volunteer techs, but this one sounds like it might be unusual. If you want to explore that route, email me at [email protected]

Peter