Friday, August 20, 2010



On pressing the power on button the set was dead as dodo. No sign of life anywhere so i suspected power supply. As usual i scanned through the power supply board carefully both sides to check for any burnt areas or burnt components and alas i noticed a capacitor which was bulging on the top silvery side. This is usually an indication of capacitor failure due to high voltage hence it’s important to consider that source peak working voltage of the capacitor when replacing. Higher voltage is better but same capacitance

Culprit: capacitor 1000uF/10v on the secondary output of switch mode power supply. I replaced by 1000uF/16V which i figured was the best for that output source. This was a design error by the manufacturer. Very commons with china made equipment.

After replacement of that one capacitor the DVD started working like new:

Below is the DVD power supply Board

DVD Power Supply
The DVD Power supply unit is Just like any Power supply unit using Switch mode power supply (chopper), so use normal PSU fault finding techniques: Start with, any power from secondary of chopper transformer, at the diodes? Usual PSU voltages are +5v,-12, +12v.If yes the power supply unit is okay, if no check for 320v across mains smoothing Capacitor. If 320 Volts is okay but no output, check for shorts on the output lines diodes, capacitors ESR gone high


Stay safe

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