How to test a thyristor B422NC

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  • LA1
    Member
    • Jun 2011
    • 23
    • USA USA USA
    #1

    How to test a thyristor B422NC

    this 3 terminal one has me baffled. between all the terminals on continuity test I get open loop(OL) On diode test I get between 1 and 3 i get 290 mV (.290) either way switching probes. Just noticed the part numbers are different, the part looks the same


    Last edited by LA1; 10-20-2023, 02:54 PM.
    Tags: None
    • stj
      Great Sage 齊天大聖
      • Dec 2009
      • 31007
      • Albion
      #2
      Re: How to test a thyristor B422NC

      its a bi-directional zener diode basically,
      the datasheet will tell you the trigger voltage

      a thyristor is different.
      similar to a transistor but only on/off nothing in between.

        Comment

        • LA1
          Member
          • Jun 2011
          • 23
          • USA USA USA
          #3
          Re: How to test a thyristor B422NC

          not sure anyway, that seems not what i am looking for. I have decided it's part of the onboard network card. I have a HP AIO 24-f0061, it's an i5. I got it for free , would like to repair it. it's getting a beep code for crowbar circuit failure. none of the fets are getting anything at their gates. the processor is getting warm though.
          looking at the pwm chip RT3602AC
          Last edited by LA1; 10-20-2023, 05:16 PM.

            Comment

            • stj
              Great Sage 齊天大聖
              • Dec 2009
              • 31007
              • Albion
              #4
              Re: How to test a thyristor B422NC

              crowbar?
              i didnt know they used any!
              well a shorted ceramic cap is most likely.
              something dead short anyway.

                Comment

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