The problem can either the 24vdc power supply is dead or the backlight inveter board is dead, so check the power supply first.
Parts: http://www.shopjimmy.com/catalogsearch/result/?q=Westinghouse+LTV-30W2+

http://s807.photobucket.com/home/budm/allalbums
http://en.wikipedia.org/wiki/Capacitor_plague
http://www.badcaps.net