You did not give a model number for this. But I will say this. I have three of these in my shop. There are no parts available for them....and they are not likely to be found. I bet your TV is right at 5 or 6 years. Thanks for asking, Matt of Martins TV Repair.
If you wish to get some details; visit the site linked here. Pull up older posts.
https://electronicshelponline.blogspot.com/
Line faults & possible causes to LCD & Plasma screen are given with illustrations. You can get an idea about the fault to an extent. Faults to all LCD & Plasma screen are almost similar, irrespective of its brand and screen size/
Tom must think the only board that is in a TV is the power board...lol...what you have going on here is the signal is going from the main to the power board that is what turns the standby to blue, and turning it on, I have a feeling you have a bad LED lamp in the panel (on this model TV its a common failure and one bad one is all it takes) and its shutting down the power supply...don't order a board before testing the LEDs in the panel as the chances of this being a power board issue are very slim with the symptoms you have.
It will be very difficult to get at open electronic market. In most cases, the original spare parts for Westinghouse brand devices are rare. https://electronicshelponline.blogspot.com/ /