Sorry to hear about your problem, I can help you today.
Sharp Tv's store error codes whenever there is a fault. After so many errors have built up it will not let you turn on the Tv until the errors have been reset. You must force the Tv to turn on (bypass error codes), and reset the Lamp Error then do a Factory Reset. Here is how to force the Tv on:
Hold [CH_DOWN] and [INPUT] on TV, plug in the AC power cord and keep holding the buttons until it comes on (try it several times cause it won't always work the first time).
If the Tv comes on it will be in service mode and you need to use the remote to set "LAMP ERROR" to 0 then do a "FACTORY RESET". Don't mess around with anything else in there or you will mess up your Tv. Be very careful.
If the Tv won't force on then it may be defective Main board or defective LCD Panel (backlighting inside).
If you need further assistance please reply here. Don't forget to click the ACCEPT button if you find this information helpful, and keep in mind that the average price of an in-home Tv diagnosis is $125!
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It would have helped greatly if you would have given this info to begin with-
You are a Tv shop.
You tried the PS.
Someone tried the Main.
You did a reset.
At this point there's nothing left but the panel, which we both know is either NLA or way too expensive to replace. We don't do panel refurb, but if the extended warranty approves it then we send it out to a place that strictly tears into panels.