Hitachi 42pd6800 black screen when turned on, got sound no picture

SOURCE: Hitachi 32LD8700 - TV won't turn on although has power

The general problem with LCD type TV's is that the power supply fails. They are very sophisticated designs that are difficult to troubleshoot and generally best to just replace the module, but sometimes there is visible damage in some of the electrolytic capacitors (visibly bulged) and high voltage rated parts can be substituted.
Hope Ya Fix It

SOURCE: black screen

first try the address board or buffer board.if this
does not repair it,the panel is defective.

SOURCE: screen went black on my 42" sanyo model dp42647 lcd

Hi there! The panel may be in protection mode. The Inverter board is the most logical area to start after checking power supply Voltages.(5,6,24 and 13Volts). There may be coils on the Inverter Board which have bad soldering or faulty. Other than this it may be main board which controls switch on or off. If all else fails, refer to a repairer. Beware of High Current!!! Best Wishes and Good Luck, Jus004

SOURCE: Toshiba 42HP66 No Picture, Only Power Works

try replaced z board Manufacturer Toshiba Part Number 75003032 Description ZSUS PCB ASSY

SOURCE: Phillips Flat TV Model 20pf4121\105 (Flashing green led)

electrolitic capacitors 1000mf /10 v in pover unit