Power is there, but TV won't turn on

Power is well connected. Product: (Vizio GV47 LF HDTV 10A)
Here's the TV's behavior:
1. It only turns on around once or twice a day, depending on how long the TV stays on.
2. Whenever it turns on, there is one "click" sound, and the orange Vizio logo turns white. When it doesn't turn on, there are TWO "click" sounds, but orange Vizio logo still remains as white Vizio log.
3. If the TV is not turned on for a complete one to two days, it will turn on the first time you try it.
4. When TV does not turn on in the first try, I turn it back off (to orange Vizio logo), wait arond 10-20 seconds, and try it again. It will turn on subject to the condition of #1 above.

Is it the power inverter? Mainboard? How hard is it to change those manually? Thanks!