SNIP
From your description, sounds like the LCD panel might still be working
even when black (use a flashlight to see if there is a display), but the
backlamps, inverter to power them, or both became defective. With
laptops, notebook, netbooks, tablets, and other small-format computers,
you have to choose to replace the backlamps and inverter, if possible,
whether to do the job yourself (hoping you get the proper kit and you
don't botch the job or damage the computer) or pay for someone else to
do it, use an external monitor, if possible, but forego portability, or
to replace the computer.

REGARDING THE BACKLIGHT INVERTER:

I forgot to mention that I swapped the inverter for the backlight using
one from another T23 laptop that has a bootup issue, but that did NOT
fix the problem.

John