Electronic – What does it mean when a capacitor and it’s connectors are marked with a red marker

capacitormarkings

Is there some kind of convention in electrical component maintenance that would explain a red marking on a capacitor?

I found this in my Pioneer SA 5300 audio amplifier and wondered if this carried some special meaning.

Pioneer marked capacitor connectors

Best Answer

Most likely Quality Assurance inspection.
For what purpose is anyone's guess (comments above are good guesses).... Here are some other ideas:

  • Such a large part as this could cause problems at or before the wave-soldering stage....an inspection to see that it is well-seated against the PCB after soldering.

  • A three-legged part with fat leads may miss a hole. An inspection to see that all three made it through their respective holes and bend over to make an acceptable mechanical seat.

  • An inspection to ensure that a polarized capacitor was inserted the right way, to save injury to the QA-person down the line who powers-it-up the first time.