Thanks for this insight.you seem to be the most knowledgable person I have come across so far on these TV's. When screen is lit the voltage is 101 vdc or more. On the LED Driver board with the set on, screen off, pin 1 on the connector to the screen is 10.20 vdc. This connection inhibits the main control board from blanking the screen upon loss of signal. Now turn the set on and the back light will stay on. Turn the set off and jumper a wire between pins 15 DIM, and 16 BLON, shorting them together. The DIM line drops from 3.4 vdc to zero when the screen blanks. With a voltmeter check the voltage on the DIM line pin 15 on the power supply board connector of the cable going to the main control board. The Main Processor board is commanding the LCD back light to turn off via the DIM control line. I'm just not sure how easy LED sets are to repair, most consumer electronics are pretty much disposable these days. The sets are probably a few years old, and I'm not the original owner, so there's no warranty, but if I can get them repaired, I will. I'd just like to find out if it's repairable.

It doesn't seem like a software thing, I'm thinking more likely a control board or some other hardware that's failing. I am glad someone else has seen the same issue at least. I am going to check with Best Buy tomorrow. Has anyone seen this issue before? Any insight would be appreciated. The sets had been installed in a restaurant, each had a cable box run to it via hdmi cable. I have been unable to find any references to this online, despite having identical units exhibiting identical behaviors. They started doing this within days of each other. Turning off the set, then back on will restore the picture, but only for a few minutes. It happens on all inputs, with or without a source plugged in. Sometimes after an hour or two, but usually after only a few minutes of use.

The screen will begin to flicker, and then cut out entirely, but the sound remains on. I have 2 Toshiba LED TV's, both are model #: 46L5200U1, that are having identical issues.

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