How to test a thyristor B422NC

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • 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
      • 31003
      • 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
              • 31003
              • 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

                Previous template Next

                Related Topics

                Collapse
                • dj8452000
                  How To Test a P-channel Trench Mosfet Using A Multimeter In Diode Mode
                  by dj8452000
                  I am new to electronics and I'm understanding most of what I'm reading but I have a mosfet on my board that I've identified as a P-channel Trench Mosfet. I haven't a clue how to test this and what I should expect to see with the multimeter probes. I am hoping someone with years more experience than myself can help me understand how to use a multimeter to read this. Please look at the drawing I have attached to this and can you try to explain to me what I should be doing with my multimeter in diode mode and what results I should expect from a good mosfet?...
                  02-18-2025, 08:28 AM
                • MalodicOne
                  macbook pro 820-02100 5v 0 amp
                  by MalodicOne
                  Unit came to me and customer said they spilled liquid on it. Opened unit and inspected board and saw no signs on liquid reaching the board. Plugged in amp meter and it pulled 20v and booted normally, i connected to internet and ran update on the OS. Came in the next day to test again to make sure unit was functional, now its stuck at 5v and 0 amps no power, no shorts found on so far.

                  Tested all CD3217 and RAA489900:
                  UF400
                  PP3v3_UPC0_LDO- 3.48v, .473 Diode
                  PP1v5_UPC0_LDO_CORE- 1.59v, .504 Diode
                  USBC0_CC1- 0v, .455 Diode
                  USBC0_CC2- 1.66v, .454 Diode...
                  Today, 10:49 AM
                • tvguy12012012120
                  Zombie Samsung UN55NU6900F dead / no standby voltage - randomly came to life after hours of troubleshooting then died
                  by tvguy12012012120
                  This is my first attempt at troubleshooting a board like this, I know I could just buy a new board but I'm curious to figure out how this works. I've been testing different components in the evenings this week and I think the problem is with the IC failing to start up for some reason. When the board is plugged in there is no standby voltage.

                  Then today it randomly sprung to life like a zombie but shortly died thereafter. I have no idea why it would have done that and its the first time I've seen it running. I discharged capacitors on the board last night, then it was sitting today....
                  02-07-2025, 05:13 PM
                • asr
                  Finding replacement diode iPad Pro 3rd gen A1701
                  by asr
                  Hello, I am looking for help to replace a damaged diode. The tristar was replaced and a diode was damaged in the process. I have a picture of the diode but dont have an exact donor. I mostly have macbooks for donors and only a few ipad and iphone boards. Diode part number: DSF01S30SCAP
                  Im not sure where to find the ipad board number. Anybody have an idea where else this diode is used on other boards? Thanks....
                  07-09-2024, 06:24 PM
                • chth96
                  How Can I test PWM DM0365R?
                  by chth96
                  Hello
                  I have power adaptor(220V/input, 12V 1.2A/output) which has symptom of fluctuating output DC voltage between 11.5V-12.2V.
                  So I opened its plastic case and when switched it on, I heard constant tik tik sound from inside its PCB.
                  I measured DC voltage between negative and positive pin of the largest capacitor(400v 10uf) and it was measured contant 300V.
                  I also measured ESR value of all capacitors and I noticed that one of capacitor(KMG 16v 470uf), which located in the secondary side, have high ESR value(10 ohm),So I replaced it with same specification NXH capacitor....
                  06-18-2025, 04:14 PM
                • Loading...
                • No more items.
                Working...