Phillips 22 inch no power high pitch transformer noise

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  • Gundesalf
    New Member
    • Sep 2014
    • 3
    • Guatemala

    #21
    Re: Phillips 22 inch no power high pitch transformer noise

    Had same problem. Did find the D688 diode defective (current flows on both directions). Before replacing it, I read the whole thread and decided to check on capacitors. I found that, although no capacitors where bulged, Capacitor C639 had produced heat damage on the board. I will try to replace the Capacitor and the Diode if possible at all. I will let you know how it goes.

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    • Gundesalf
      New Member
      • Sep 2014
      • 3
      • Guatemala

      #22
      Re: Phillips 22 inch no power high pitch transformer noise

      Also found heat damage on Resistor R637. So here is my shopping list:
      - Diode replacement for D668: 1watt, 20volts
      - Capacitor replacement for C639: 220uF, 10volts
      - Resistor replacement for R637: 0.25watt, 120**-Ohms

      Correction: "D688" on my previous comment was a misstype. It was "D668"; the same that showed problems for Tonymon1.

      Comment

      • Gundesalf
        New Member
        • Sep 2014
        • 3
        • Guatemala

        #23
        Re: Phillips 22 inch no power high pitch transformer noise

        I am currently typing this reply using the repaired Philips TV as a computer monitor. I only replaced the D668 diode. The capacitor and the resistor tested ok, so I kept the original ones.

        Thanks.

        Comment

        • rustytierod
          Senior Member
          • Sep 2014
          • 81
          • USA

          #24
          Re: Phillips 22 inch no power high pitch transformer noise

          Would a shorted diode cause picture to fade to white over 5 to 10 min?

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