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Things You Should Know About Sony Power Supply Boards

Power supply boards are needed to operate LCD TVs. They convert the household power supply into lower voltages that the TV can use for various purposes. Here are some of the things you should know about how the boards work.

How do power supply boards work?

Household power supply lines typically carry 110 volts. The voltage is too high for many features of the television, and it has to be reduced so it doesn't damage different parts. The power supply board regulates and reduces the 110 volts to manageable levels for the TV's sensitive parts to withstand. An example includes the microprocessor, which needs a constant supply of five volts to keep it awake during standby mode. If too much power went to the microprocessor, it could overpower it and burn it out. The board also sends between 12 and 18 volts (depending on the make and model of the TV) to the audio circuit and 24 volts to the inverter board. See the manufacturer site for details.

How can you tell when a power board needs replacing?

There are a couple of things that can happen to let you know the board managing the power supply needs to be replaced.

  • The TV will not turn on, and there's no sign of power going to it.
  • The capacitors are bulging out and have become deformed.
How do you replace a power supply board?

The first thing you have to do is remove the back panel from the television to expose its internal parts. Locate the power cord to the television and follow it to where it attaches to a printed circuit board inside the TV. This will be the power supply board. Here is how you replace it:

  • Unplug the television, and ensure that no power is going to it.
  • Remove all the electrical cable connections attached to the board.
  • Remove the screws from the power supply board, and take it off the back of the TV.
  • Check the model and serial number on the board, and get an exact replacement part.
  • Screw the replacement power supply board in, reconnect the cable connections, and put the back panel on the TV.
Can you just replace the capacitors?

You can, but you have to know how to remove and place fresh solder on the board. If a capacitor needs to be replaced, you first have to remove the existing solder holding it in place. Take the capacitor out and solder the replacement part in its place.