Why does regulator run hot in 42lx196 toshiba?

Over-voltage protection. The output voltages from the main power regulator board is more/less than normal. If you wish to get some details, check the site linked here. http://electronicshelponline.blogspot.com/ Pull up older posts.

Sounds like a power regulator board fault. Voltage comes out from it might be less or more than normal. These blinks are fault indication, and known as blinking codes. From the number of blinks occur at one time switch ON; you can get an idea about the faulty circuit stage inside the TV. This will make repair easy. For more information, check the link http://electronicshelponline.blogspot.com/

hard cover i gat it

I had same problem, i just replaced the power capasiters on the board an solved it...look for mushroom heads or bottoms on them an swap them out an it should be it. And if thats it then buy the higher temp capasiters so it wont happen again..

Hello
Just unplug the TV from AC power socket, and wait for just 10 minutes. Doing so, if the fault is due to reset; will be rectified. If this does not help you, make sure that there is some short circuit with the inside circuit boards. Normally, if backlight inverter has a short, this type of fault can occur. You must have through knoledge in electroncis and some expereince in servicing TVs to follow. By hard reset [by unplugint it out from AC poser socket] does not help you, and you haven't enough knoledge in electonics, it will be best for you get this TV repaired by any experienced service technican, or by the authorised service center for Toshiba at your town. OK.

I have the same model and the same problem. I was watching it when I heard a loud "pop" and the screen went black and got no response from any controls. I paid $50 at a repair shop to tell me it was the power supply board and would be an additional $275 to fix. I chose to buy another tv but am searching for the part. Here are part #'s - 75003371, PE0071G-1. Some online stores have carried it for anywhere from $70 to $200. The cheapest I have found in stock anywhere is $150. Just google those numbers.

main power board needs to be replace

it is the power supply if you know how to soder you can just change the switch for 20 bucks

the problem is the main power board you can ither change the whole board or change the STR-W6765 Primary Switching Regulator.

You don't need it. I have Directv also. I would call them up to find out what happen to the missing local channel. It should be included in your subscription.