No picture on toshiba 42" flat screen tv

SOURCE: 42" Toshiba Plasma TV no picture or sound

My experience with 42" plasma tv's with no picture or sound was a missing power supply voltage. On the power supply board check voltages on the plug. The voltages should be marked on the board,

SOURCE: TOSHIBA FLAT SCREEN TV has black screen but power light is on!?

Try resetting the TV by leaving it unplugged for an hour.
Plug it back in and check to see if it works normally.
If that doesn't work, rule out the Directv box by pressing the reset button near the access card. The box could be putting out a signal that doesn't have video or audio.
If everything fails, have the tech man come back to check everything that he did before you use the warranty on the TV.

SOURCE: Green light but no picture, no sound

Your mainboard is damaged, replace it and that will solve your issue.

SOURCE: 47inch toshiba lcd tv (HL167) black picture, but

Best to replace both at the same time . Yes they are easy if you can find the parts.

SOURCE: Toshiba REGZA 42

The 2 long boards call the LCD inverter boards are dead.These 2 long inverter boards help the LCD screen to have backlight to produced a picture.These 2 long LCD inverter board are dead,must be replaced to get a picture again.Tries websites like Shopjimmy.com,Ebay.com to buy these 2 refurbishes long LCD inverter boards for the replacement.