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

backlight has failed or the inverter circuit that powers the backlight has failed
LCD TV needs a backlight for you to see the LCD

i moved you to TV from computers.
can you see the video on the screen with a flash light.??? i bet yes.
all LCD have back lamps. that must work or turn black, or dim
use flashlight first to see data/tv presentations,,

this TV is 9 years old today
this TV has CCFL back lamps (sell it and get LED TV)
here is page 37 in your manual (ive never seen one last 9 years)
quote
The cold cathode ? uorescent lamp used for the back light on this TV has longevity. When
the brightness of the screen comes down,
or the ? ckers of the screen are caused, or
some parts of the screen do not light up,
it may reach the end of its life. Contact a
service technician.
end.

Do this test first. With the TV on normally, shine a flashlight on the screen. look for a dim moving picture.
1) If you see one, the backlight led driver isn't working.
2) If you DON'T see a picture replace the T-Con board.
You can get parts here: www.shopjimmy.com TV Parts Universal TV Stands DLP Chips ShopJimmy

perform the 'Flashlight test'
. LCD LED TV Repair No Image Blank Black Screen Flashlight Test How to Fix...

Shine a flashlight on the lcd up close when it is on. If you can see the picture, it is the inverter

Sounds like main board fault. Contact any service technician to confirm. If you wish to get some details; check the site linked here. Viewing it in "Mosaic" will make surf easy.
http://electronicshelponline.blogspot.com/

Dim the lights in the room, turn on the set. Shine a bright flashlight on the screen, do you see a faint picture?

Probably a bad T-CON or LCD controller board, Toshiba calls it a "Seine" board.
Parts are available here www.shopjimmy.com

My guess would be to suspect the inverter. but from what i can tell that model had two possile inverter types used during production.
toshiba P/N 75008432 Rev C3
AND
75008433 V470H1-L

Sounds like the back light is out, and the unit needs servicing. You can check this by shining a flashlight close to the surface, and if some image is seen, the the back light is the cause. Else the LCD driver is gone.