Sony TV Repairs – How to Install Main Power Supply Board

Sony Wega TV Repair. TV Replacement Part.

A Sony Wega DLP TV was suddenly turning ON & OFF because a faulty main power supply. Our TV repair technician, will show you how to install the main power supply board with demonstrative pictures.

Please remember that the TV has high voltage and can kill you if you touch the wrong part. Make sure to unplug the TV set for a few hours before making the repair. Do not attempt the repair if you are not a technician.


After you remove the back Cover of the TV (fig. 1), you should start to uninstall the chassis.
The main power supply is located behind the Chassis.

  1. Uninstalling the Chassis:
    • The chassis is connected to the main TV body and to the power supply board with connectors, wires, and different sizes of screws. Some parts of it are covered with metal pieces. (fig. 2)
    • Disconnect the wires and connectors carefully.
    • Remove all the screws and put them in a safe place.
    • Remove the all the metal pieces and put them in a safe place.
    • While you are taking the chassis out of the TV, take it out slowly because it would be still connected from behind with more wires. So, with each pull; look if there is a connected wire, disconnect it then move on slowly. (fig. 3)
  2. Uninstalling the Main Power Supply Board:
    • After you have located the chassis on a safe table, start disconnecting the power cables and small connectors from the board. (fig. 4)
    • There are very lean and fragile connectors, be careful while unplugging them
    • Wiggle the chassis before attempting to remove it. And prepare a safe place to put the chassis after you uninstall it. (fig. 5)
    • The chassis is not only connected to the board, it is also connected to the main plastic housing.
  3. Remove the old power supply board slowly; it is stabled with the plastic housing by small clasps. (fig. 6)
  4. Install the Power supply board:
    • Make sure you are replacing the board in the right direction.
    • Slide the board slowly and smoothly under the clasps of the plastic housing. (fig. 6)
  5. Re-join the Chassis to the board
    • Keep wiggling the chassis until you replace it to the back of the plastic housing carefully. (Make sure not to replace it on any wire, remove the wires aside first then try to fit it in the outlets) (fig. 7)
    • Warning: the chassis is not fully stable yet, hold it with one hand and reconnect the wires and connectors with the other.
    • Put the screws back in and make sure the chassis now is stable and well connected to the board and to the plastic housing.
  6. Installing the chassis back into the back of the TV:
    • Position the chassis in-between position before pushing it into the TV (fig. 8)
    • Start re-connecting it to the wires inside the TV
    • Push it slowly so you won’t tear or smash any connector or cable accidentally
    • Put back the all the metal pieces covering some sensitive parts in the chassis
    • Put all the screws back; make sure you do not misplace any. It is very difficult to take it back when the screw is put in a wrong gap.
    • Connect back the wires and connectors carefully. Some of them look very similar; make sure they are in the right jack.
  7. Replace back the TV plastic cover.


  1. Wiggle the chassis every now and then to see if it is disconnected before unplugging unnecessary connectors.
  2. Take a picture for all the connectors in case you forgot their original places when you want to install them back.
  3. Before uninstalling the chassis, prepare a safe table close to you, to put it on after you have disconnected it from the TV.


Don’t risk causing more damage to your product (or yourself!) by attempting to fix it on your own. It’s also easier and quicker for a service technician to diagnose and fix a problem when the product is assembled. In the end, to save time and money, fill a repair form on line and AAAA TV repair Store will help you to repair your TV in home or in store.

You can see a video here: How to Install the Main Power Supply Board on a Sony Television