Insignia NS-LCD32_7D21 power supply

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  • budm
    Badcaps Legend
    • Feb 2010
    • 40746
    • USA

    #1

    Insignia NS-LCD32_7D21 power supply

    Got this one in today (made in year 2007), the unit has standby voltage, but when power ON is activated I can hear small buzzing/sizzling sound from the power supply. The heatsink for the MOSFET PFC, Diode gets hot fast. The 12v has about 4v, the 24v has about 6V output.
    Check the DC voltage on the main cap (150uF 450VDC) in standby, it has about 120VDC, put meter in AC mode to read AC voltage on the cap, it shows 80VAC!.
    Remove the main cap and test the value, it shows about 30uF, ESR is off the scale, more than 10 Ohms.
    Put in new main caps, TV now works good, replace the rest of the caps, will be burning in for about 1 week.
    Attached Files

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    Never stop learning
    Basic LCD TV and Monitor troubleshooting guides.
    http://www.badcaps.net/forum/showthr...956#post305956

    Voltage Regulator (LDO) testing:
    http://www.badcaps.net/forum/showthr...999#post300999

    Inverter testing using old CFL:
    http://www.badcaps.net/forum/showthr...er+testing+cfl

    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
    http://s807.photobucket.com/user/budm/library/

    TV Factory reset codes listing:
    http://www.badcaps.net/forum/showthread.php?t=24809
  • capkid
    Badcaps Legend
    • Oct 2010
    • 1339
    • United States

    #2
    Re: Insignia NS-LCD32_7D21 power supply

    I'd never heard of Jianghai caps. It appears to be a Chinese company.
    LG Plasma Mal-Discharge Correction Service

    Comment

    • R_J
      Badcaps Legend
      • Jun 2012
      • 9623
      • Canada

      #3
      Re: Insignia NS-LCD32_7D21 power supply

      The top of that cap (picture 6) looks a little pointy, I'll bet if you take the plastic off the top it will have poped.

      Comment

      • tom66
        EVs Rule
        • Apr 2011
        • 32560
        • UK

        #4
        Re: Insignia NS-LCD32_7D21 power supply

        Nice fix! Lucky it did not blow the PFC, that usually happens with bad output cap.
        Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
        For service manual, schematic, boardview (board view), datasheet, cad - use our search.

        Comment

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