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How to test a thyristor?

Discussion in 'Electronic Repair' started by Infinity^2, Jul 20, 2003.

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  1. Infinity^2

    Infinity^2 Guest

    I am working a a Daytek DT-1704C 17" monitor. It powers up with no
    HV. I was prodding around the power supply unit and inside is a
    TF341M thyristor (I looked up the datsheet). Using the diode test on
    my DMM it measures 0.266V between gate and cathode both ways. Is this
    normal? or can a thyristor even be tested with a DMM? If the part is
    bad I suspect it is preventing some sections of the monitor from
    receiving power. Any advice is appreciated. Thanks.
  2. + o----+-----/\/\---------+-----o Test+
    | 100, 2W __|__
    | _\/\_ Device Under Test - DUT
    12 VDC | R2 / | (SCR or triac).
    +---/\/\---o <--' |
    1K o |
    | |
    - o----------------+------+-----o Test-

    Apply the 12 V. The device should be off.
    Touch the gate R2 - it should turn on and stay on.

    --- sam | Sci.Electronics.Repair FAQ Home Page:
    Repair | Main Table of Contents:
    +Lasers | Sam's Laser FAQ:
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