Samsung LN46A630M1F :: Power Board Troubleshooting

Repair Summary

This device came in failing to power on as expected. When the power button was pressed the device would sometimes power on with no issues, and other times it would seem to loop between powering on and powering off until it finally would remain on and function as expected.

These symptoms are commonly associated with capacitor failure on the power board. I removed the back cover and stand then inspected the electrolytic capacitors on the board, but did not discover any visible failures. After some research into this specific model I identified seven suspect electrolytic capacitors on the Power Board near the Main Board Connector.

Fortunately, I had all of the capacitors I needed in stock so I swapped them in which seems to have resolved the issue entirely! I've included photos of both sides of the board below and some close-ups of the failing components along with replacements for reference. If you're having the same symptoms replacing the capacitors in the general area is a good place to start when attempting to repair the Power Board. I used replacement capacitors that are rated for a higher voltage than the originals because Samsung did not use appropriately rated capacitors on this board and that is why they have such a high failure rate. A replacement with the same voltage rating would likely also fail is short-order (under a year).

Original Parts

  • 4 x 1000uf 15V Electrolytic Radial Can Capacitors
  • 2 x 470uf 15V Electrolytic Radial Can Capacitors
  • 1 x 47uf 10V Electrolytic Radial Can Capacitor

Replacement Parts

  • 4 x 1000uf 35V Electrolytic Radial Can Capacitors
  • 2 x 470uf 35V Electrolytic Radial Can Capacitors
  • 1 x 47uf 50V Electrolytic Radial Can Capacitor