Is this rectifier dead - BYC8-600 ?

Discussion in 'General Electronics Chat' started by UnnamedUser159, Sep 30, 2016.

  1. UnnamedUser159

    Thread Starter Member

    May 3, 2016
    130
    0
    I see
    0.365 between cathode 1 and anode
    0.365 cathode2 and anode

    and the other direction shows:
    .0L

    :)

    It`s from computer power supply.
     
  2. #12

    Expert

    Nov 30, 2010
    16,345
    6,831
    0.365 whats?
    On what range of the meter?

    I think they are Shottky diodes and they are good, but you really must provide more information.
     
    MaxHeadRoom likes this.
  3. RichardO

    Well-Known Member

    May 4, 2013
    1,238
    385
    Also, are these measurements done out of circuit?
     
  4. bertus

    Administrator

    Apr 5, 2008
    15,649
    2,348
    Hello,

    The BYC8 is a single diode.
    The cathode is also connected to the tab.

    Bertus
     
  5. UnnamedUser159

    Thread Starter Member

    May 3, 2016
    130
    0
  6. ci139

    Member

    Jul 11, 2016
    341
    38
    Last edited: Oct 1, 2016
  7. UnnamedUser159

    Thread Starter Member

    May 3, 2016
    130
    0
    So it`s good or bad? :)

    I just know what should be the forward voltage as the rule for the diodes (silicon) - between 0.5 and 0.8.

    I think you are talking that i have to see 2.8 on the digital multimeter and the diod has failed but have to ask
     
  8. ci139

    Member

    Jul 11, 2016
    341
    38
    the general thinking goes that in ?"normal" operating conditions the voltage drop on PN junction is something 0.6 to 0.8V
    while in small signal oscillator circuits the lower limit for diodes is somehere 270mV and BE junction 380mV
    depending on diode the large signal maximums may go over 2V

    the good or bad depends where you intend to use it
    as what i can come up from datasheet it's not used as rectifier rather reverse diode for mosfet or gate protection
    random find for FR rectifier STPR1620 has somewhat half the voltage drop of that on BYC8-600
    witch makes it more considerable to be used and for rectifier bridges - while the latter i wouldn't put there
     
  9. UnnamedUser159

    Thread Starter Member

    May 3, 2016
    130
    0
    My head is getting more and more confused.

    I have one computer PSU and i have desoldered the heat sinks from the board and check the elements that are linked to them.
    The MOSFETs i check on the heat sink.
    Took off the diod from the heatsink and want to check it.

    "We have" main rule for voltage check for diodes out of board.
    I want to understand things and really make one (to not say what) repair.

    How many types of checks are avialable i really go mad...
     
  10. ci139

    Member

    Jul 11, 2016
    341
    38
    if you go mad make it beneficial as energy source for staying alert
    (join local martial arts club to get better insight while required)

    what you did (FW conductance path verified, BW blocking verified) is usually sufficient

    hypotetical : if your diode hadn't significant conductance at below 1V your std. meter's "diode FW cond. check" might had failed
    so alternate procedure : is constant current or current limit and sufficient higher voltage voltage source
    also may be needed for darlingtons´ base emitter FW conductance
     
  11. BR-549

    Well-Known Member

    Sep 22, 2013
    2,004
    394
    I have never checked an isolated diode, with a multimeter, on the volts setting.
     
  12. ci139

    Member

    Jul 11, 2016
    341
    38
  13. UnnamedUser159

    Thread Starter Member

    May 3, 2016
    130
    0
    So we go in this case
    0>0.4V >> Short ?
    I dont see the diod to be Shottky in the PDF so it has no excuses/:)/ to does show these voltage if it`s not shorted.

    Sorry for my last Reply. I was nervous
     
  14. ci139

    Member

    Jul 11, 2016
    341
    38
    i get nervous when the computers (world.processes) are slow - that means - almost uninterrupted
    that's why i have to file my nails - they go numb of drumming the table :confused::cool: continuously
     
  15. UnnamedUser159

    Thread Starter Member

    May 3, 2016
    130
    0
    It`s me again.

    Prepare you tranquilizers :D

    About the diod ok. I am pigheaded.

    When i read about atx repairing i see on the heat sinks "some elements".

    In them i dont see Bridge Rectifier with 4 pins. >> dont have info about them checking.

    Is there a authoritative way to test it out of circuit and unmounted from heat sink ?
     
  16. ci139

    Member

    Jul 11, 2016
    341
    38
    you're complicating your life coz your testing limits are set by an availability of the schematic you debug e.g. what nearby components can be shorted off / cut out from your test e.c. or you must already be experienced of testing it under limited operating conditions knowing the proper operational voltages at the check points + have a good equipment×methodology to know whether your test results are credible
    ?? re your question :oops: what ATX model# you have in hand - the component there
    (the general solutions always more complicated than specific ones) ♪♫
     
    Last edited: Oct 20, 2016
  17. ci139

    Member

    Jul 11, 2016
    341
    38
  18. renemonte

    New Member

    Oct 7, 2016
    13
    4
     
  19. renemonte

    New Member

    Oct 7, 2016
    13
    4
    the diode is o.k. a diode in a pwr supply usually shorts first, then breaks open due to excessive current.this is why, when tested,it shows an open
     
Loading...