I'm trying to identify a short on a PCB and I've come across this component that I think may be the culprit, but I'm unable to find what it is so I can look up its datasheet.

If anyone can help identify this so that I can attempt to remedy, I would be very appreciative.

photo of unknown component

  • 1
    \$\begingroup\$ It might be a relay or optocoupler. Can you give us more context - what does the board do and a view of the surrounding parts. \$\endgroup\$
    – Kartman
    Commented Oct 21, 2022 at 4:17

1 Answer 1


That is an RF transformer manufactured by Mini-Circuits.

Here's the datasheet.

And yes, you should read a short across the three terminals on each side of it. Probably not the source of your problem.

You can get an idea of what's inside one of these and how they're used from this appnote.

  • \$\begingroup\$ I should think that a blown transformer (read: short across all or at least part of the windings) might very well be the culprit. \$\endgroup\$
    – arne
    Commented Oct 21, 2022 at 13:46
  • 4
    \$\begingroup\$ @arne When someone says they're trying to track down a short on a board they usually mean a short on power. This is a broadband RF transformer, it will only have a few turns of wire to begin with, it's not very likely to short, and even if it did it wouldn't pull down a supply. Those windings are going to be a fraction of an ohm at DC. I'd guess the OP was probing with an ohmmeter, measured a short across the pins and not knowing what the part was didn't know that they're supposed to be that way. \$\endgroup\$
    – GodJihyo
    Commented Oct 21, 2022 at 15:12
  • \$\begingroup\$ Thank you very much :) The controller is reporting that this part of the circuit has a short (It's a very bespoke long range, 2 wire communication + power circuit) and going back from the terminals to systematically eliminate components had me stuck at this one. I shall continue my probing and see where it leads me now! \$\endgroup\$
    – Justin
    Commented Oct 24, 2022 at 22:26

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