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I need help identifying an SMD component it is a small(1 mm X 1.5 mm) black part with an "O" written on top if it. I think it is a Schottky diode for reverse polarity protection ?.

(Source, first part on codes beginning with O)

I have attached an image if that helpscomponent J2/J3

The component in question is marked J2/J3 on the silk screen. Also, if it helps the image is of a remote control pcb.

PS: This is my first post so please let me know if i did something wrong :)

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    \$\begingroup\$ Welcome to EE StackExchange. It looks like zero ohm resistors. They are often used for configuration purposes if you have a variant of a PCB that needs to have some connections that another variant doesn't. \$\endgroup\$ Mar 19, 2019 at 7:55
  • \$\begingroup\$ ok thanks. Also can you tell me what the 'J' on the silk screen usually stands for like a 'U' stands for an IC ,'R' for resistor ,'C' for capacitor etc. \$\endgroup\$ Mar 19, 2019 at 8:09

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These are 0603 zero-ohm resistors - the "O" is actually a "0". Basically it is a solder jumper or jumper wire but in a machine assembly friendly package.

On single-layer boards these are often used to assist routing and jump over traces. This appears to be the case for J2 and J3.

They are also frequently used for changing configuration pins. You typically have two resistor footprints, one to VCC and one to GND. On this you can place a zero-ohm resistor on either footprint to pull the configuration pin low or high. This is sometimes known as "strapping" and appears to be what OP3 is used for.

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  • \$\begingroup\$ Thanks :) I upvoted your answer but it did'nt count as my account is very new. :) \$\endgroup\$ Mar 19, 2019 at 8:14
  • \$\begingroup\$ You can accept the answer, which is more or less the same as upvoting. \$\endgroup\$
    – Huisman
    Mar 19, 2019 at 8:23
  • \$\begingroup\$ Just found out that there is a feature for accepting answers :) \$\endgroup\$ Mar 19, 2019 at 8:30
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I think it is a Schottky diode for reverse polarity protection

Very unlikely. A diode should have a different package, and a diode would usually have its cathode terminal marked.

You have a 0 Ohm resistor here, the label "J" may be because it's used as a jumper (see Peter Karlsen's comment).

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  • \$\begingroup\$ Ahhh... thanks for clarifying I was wondering what the 'J' stood for :) \$\endgroup\$ Mar 19, 2019 at 8:16
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That is an 0 Ohm Resistance. they also called SMD jumper resistors.

They are used as wire links to connect the traces on Surface mount boards, which can be assembled using pick and place machines easily. (same like jumper wires in through holes boards) and as well as changing the routing in pcb's

the size 1mm * 1.5mm indicates that it is 0603 SMD package.

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