The wonderous CCFL flash light trick.           

The screen is 100% black all the time.
"The flash light trick" Desktop or LapTop  (just 1 minutes work and bingo ?)

I take my flash light, and point it to my black dead screen.  (I am hammering the ESC key, "flashlight pointed to screen, power on and quickly hammer the ESC key" BAM BIOS POPS. (or F10 key on 10 year or older HP)
or if you know windows is running, you heard it make music, ? or just  know it by the sounds of the HDD etc,,, then just use the flashlight, now. BAM, yah, got  DATA?
If I  see data here, this is BIOS but can be Any windows screen of any kind ,or even a login screens or BLUE SCREENS 's. See, it's not dead is it; only the Back lamp is DEAD, (the CCFL must be replaced)
This is the first CCFL test. (mostly before year 2010 PCs)  If testing any Desktop there you will see the monitors log show up , and then PC BIOS showup here.
      Wow the back lamp is dead ! but data is NOT DEAD !!!

When I see the above, (I have repaired many )  but I can  get this Desktop  monitor from walmart for near $50 and use it.  or a whole PC for  way  less !!
One can use a Desktop screen on your laptop in  pinch or at any time. (mobility here will cost you way more,  labor and parts.
All HP LT have service book telling you the steps to remove this screen and put back the new one. (some LT have no separate inverter cards but deep planted the display."hidden")

But if portable is necessary, then you must fix it, and below that is what I am doing.... (some just use and VGA external monitor for , cheap cash used and use  that forever)

Keep in mind that the LCD connector deep inside might just fall off, for sure if monkeys played here before and did not put back the tape to secure it like new.
This is what is dead, just one small example. Those TUBES ARE DEAD.  He's dead Jim. or the inverter puked. (99% are tubes bad)

On laptops one can buy a whole new panel for $50- top 100 bucks.
On monitor, for a desktop mostly you destroy more that you correct, there.  (imagine plastic and glue sandwich)

version 1.  12-9-2017