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Comments on What are these mystery components (one of wire coil, another labeled "100-10L A9")?

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What are these mystery components (one of wire coil, another labeled "100-10L A9")?

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I have here an acre-counter or crop counter device like the lykketronic shown below, using two AA batteries. It arrived without working. lykketronic acre counter

Upon opening its case, I found that the PCB is missing two components, and the area where these components were is scratched, as though someone removed them carelessly.

Here is a photograph of the main PCB. The top part (cropped) is just the LCD.

PCB entire

And a close-up of the corner missing the components.

I was able to find another identical device, and the components are intact. One is a coil of wire on a black spool with a rectangular top. The other is a rectangular box labeled "100-10L A9". Here is a general view:

sane PCB

And again the close-up, including the mystery wire coil component: wire coil component

Is this wire coil a filter of some sort? An impedance? What does it do?

And what is the black box to its left? It looks like an SMD capacitor like this one at mouser, but I don't know how to interpret its label.

I am hoping to either replace or re-make the components to restore the PCB.

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4 comment threads

It arrived without working (2 comments)
[meta] component ID questions and repair questions (1 comment)
What's the output of the SOT-89 chip with the 331 marking? (2 comments)
What's connected to the [-] and [+] throughole pads? (4 comments)
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The component with the coil of wire is an inductor. Judging from the small size, it is probably only a few µH. There are lots of uses for inductors, like for filters, switching power supplies, tuned oscillators, and others. I would not try to guess the use from this scant information.

The component to the left of the inductor in second picture looks to be a diode. It only has two terminals. The stripe at one end probably marks the cathode.

Added

Lundin has pointed out that the black component on the left is probably a tantalum cap, not a diode. In retrospect and given the markings, I agree that it is a definite possibility that I just didn't think of earlier.

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1 comment thread

Tantalum cap (1 comment)
Tantalum cap
Lundin‭ wrote about 1 month ago

"The component to the left of the inductor in second picture looks to be a diode. It only has two terminals. The stripe at one end probably marks the cathode."

Nope, tantalum caps, the stripe marks + since they have polarity. And they like to explode :)