OK,I've replaced the Power Control Board and the Main Board but when I plug the tv in the blue light comes on the makes a low pop and then the red comes on then the blue,pop etc.What is the cause and sollution to this?I thought maybe the power supply is shot?Oh yeah my TV is a Polaroid TLA-04011C LCD TV.

Possible TCon board issue but check Pico fuse on Power Supply. Fuse is located near top left closer to connector plug . Fuse is marked as L7.
If faulty, replace ONLY with the correct value and type of fuse.

HI Ray....unhook the plug going from the power to main board and see if you get backlights when you plug the set in, if you do chances are you have a bad replacement main

What makes you think the main board is bad? In sets that act totally dead 3 out of 4 times it's the power board, if your ok doing this take the back off and look on the power board for the connector that goes to the main board and see if you can see a ps-on pin, you need to see around 3 volts there, if you don't the power board is bad, if you see it then it's a main

road kill should be left where found

Hi i would need more info. what is the model number. its not always the power board it can be a processor fault. and thats the main av board. the processor is what turns on all the parts to start up.

Fault at its main digital board. Short circuited component/s at it. Contact any service technician; or the authorized service center. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts.
http://electronicshelponline.blogspot.com/
In most cases, the main board might have to be replaced. If so, a software [firmware] update too might be necessary.
Before going further; try a hard reset first. If it does not help you, replace the main digital board. There are two methods to reset TVs. The first is simple to do; a Hard Reset. The other is somewhat skilled; is a Factory Reset (System Reset). To make it a hard reset, just unplug the TV from AC mains wall socket, and re-plug it back after 15 minutes or so. If you do this by overnight is better. This procedure will make it a hard reset. If you want to make it a system reset [Factory Reset]; you have to enter its service mode option, and select the factory reset option. If you wish to get some details; visit the site linked here.

Main board fault. If you wish to get some details; check the site linked here. Viewing it in "Mosaic" will make surf easy. Surf the site with patience. Pull up older posts.
http://electronicshelponline.blogspot.com/

replace the power supply board.

The main power supply regulator board has the fault. Check if any electrolytic capcitor/s has bursted out. Replace them if any. If this do not help you. repalce the board as card basis.
Replacing it as card basis is fine, rather than making 'surgery' to it.

Have you had any luck with your Technics piano? I've got the same piano and Mine does not work either. No lights on the control panel, only red power light comes on. Does yours have any led lights besides the power light that come on? I've investigated and I have learned a lot from this piano. 4 main boards. Im pretty sure I've got it down to one board. Interested in selling me any boards from your Piano??