Tv keeps turning off - LG 42LC2D 42 in. LCD HDTV

Scenario 1: The TV turns on then shuts right off

• In this case, the power supply unit is being loaded down by any of the boards it supplies. A short circuit is being detected in any of these boards. These boards are connected to the indicated connectors on the power supply unit shown below.
  

• The resistance, both in reverse polarity, of the cables from the boards specially the ones with indicated voltages need to be checked. Short circuit is present when resistance on both instances is zero.
  
• The board with the indication of a short circuit must be replaced.

• A heat sink overheats. Make sure the TV is placed at least 4 inches away from the walls. This will allow proper air circulation. You can also provide a fan. Have it checked by a qualified technician to prevent further damage.
  
• The power supply is faulty. It is usually caused by leaky or bad capacitors like the ones shown below.
  

• Replace the capacitors with the same specifications.