You can find tutorials onhow to dismantle your TT here
:link:Hard to tell if it is the backlight or the driver circuit, only way to be sure is to test it.
You can find complete displays or just the LCD part without the touch pad on Ebay, sometimes it is good to go to the chinese Ebay site and use the translation.
Last time I checked a complete display was about 25$ incl. postage and handling.
Most TT displays are compatible, so check for the manufactures and serial number on your display before ordering.