Have a TDA-03211C Polaroid TV. It doesn't turn on, How do I know that the tv has the power supply broken?

This is what you need to do:
1) Look to see if the power supply module has any caps with leaking/bulging tops.

2) If you do have any indicator lights on the front panel, then it means the Standby 5vdc power supply section is working for the main logic to operate. Look at the termnials of the power supply that is labeled with STBY5V or something like that. This is a MUST HAVE voltage to get th TV started.
3) When the power button is activated, it will send out turn on signal #1 to the power supply module to turn on the main 5vdc (for the rest of the logic ciruites), 12~16vdc (for sound power amplifiers), and the 24vdc (for the backlight inverter board). Another turn on signal #2 is sent to the Backlight on/off control pin on the inverter board. Signal #3 is for turning on the T-CON board LCD panel.
It uses all these turn on signal so when the TV is in standby/sleep mode it will not consume all these power to save electricity and pass Energy Star compliance.

So now you have some basic ideas how LCD TV works and what is needed to turn on the TV.
Check out those voltages before it is on and after it is on

http://s807.photobucket.com/home/budm/allalbums
http://en.wikipedia.org/wiki/Capacitor_plague
http://www.badcaps.net.

Tries websites like Shopjimmy.com,Ebay.com to buy a refurbish power supply board for the replacement.