Problem with an Arc LS circuit.

[Sinjz]

I've got a problem with an Arc LS2 circuit. Well it doesn't work. :sigh:

I've taken it out of the body and played with it a little. The emitter is fine as it lights up when I touch both contact pads with wires connected to a CR123.

The gold negative contact around the bottom border of the board works. I touched that with a wire and the positive contact pad of the emitter at the same time and the emitter lights.

What does not work is when I touch the center positive contact at the bottom of the board and the negative contact pad of the emitter. Emitter does nothing. What do you think the problem is and is there a simple fix? :thinking:

Also anybody know where I can find some R15 resistors for this thing cheap? I want to boost the current in this and my other Arc LS.

Thanks!

 

[greenLED]

What does not work is when I touch the center positive contact at the bottom of the board and the negative contact pad of the emitter. Emitter does nothing.

What does it do when you complete the circuit by touching the center (+) contact and the (-) contact ring on the board?

 

[Sinjz]

What does it do when you complete the circuit by touching the center (+) contact and the (-) contact ring on the board?

Nothing.

I tried both and figured I'd say the emitter contact pad, in my example, because that would eliminate the negative contact ring from being the problem. I think I'm getting these terms correct. Contact ring is the gold colored part on the bottom border of the board, right? Looks like the letter "C"

 

[chimo]

Do a continuity check between the battery contact pad and the inductor. A circuit trace may have broken.

 

[Sinjz]

English please.

How do I do this continuity check and is the inductor the thing with three red dots on it? :thinking:

 

[chimo]

English please.

How do I do this continuity check and is the inductor the thing with three red dots on it? :thinking:

Do you have a multimeter? If so, there is sometimes a continuity check function on it. If not, you could use the resistance setting.

You should read a very low resistance between the battery contact and the inductor (either contact). Yes, the inductor is the one with the dots on it (1 red, 2 orange??)

 

[Sinjz]

I have a multimeter. No continuity check though.

I set it to the resistance function (2000) and touched a battery contact and a inductor contact. The screen flashes from 1 to something like 1153, for about a second or two, then back to a 1, even when I don't remove the probes.

Does that tell you anything??? :thinking:

 

[chimo]

I have a multimeter. No continuity check though.

I set it to the resistance function (2000) and touched a battery contact and a inductor contact. The screen flashes from 1 to something like 1153, for about a second or two, then back to a 1, even when I don't remove the probes.

Does that tell you anything??? :thinking:

The resistance should stay low. You may have a broken trace - does the flex board have any cracks?

BTW, I am flying out of town in the morning for the remainder of the week (if I don't get back to any more of your questions). Good luck,

Paul

 

[Sinjz]

The resistance should stay low. You may have a broken trace - does the flex board have any cracks?

BTW, I am flying out of town in the morning for the remainder of the week (if I don't get back to any more of your questions). Good luck,

Paul

Is the 1153 considered low? Am I reading the R15 resistor there?

No obvious cracks that I can see, but honestly I don't know what I'm looking for. Again, none of the traces seem to be cracked or broken to me though.

Thanks for the help and no worries, I'll just bug you next week. :laughing:

Seriously, I hope this info is helping someone figure out what the problem with the board is.

 

[chimo]

The resistance should be close to zero. You will heve the DMM lead resistance, trace resistance and the DC resistance of the inductor (depending which side of the inductor you meter). A reading of an ohm or so shoudl account for the above resistances.

See the following pic. It's not exactly the ArcLS circuit but it will give you an idea where to check for continuity.