Laptop will send video to another monitor, but the screen is on the laptop itself is barely legible, almost like contrast is blacked out. I tried hot keys to increase the brightness and no luck. I am guessing power inverter for lcd or lcd itself?
Your backlight or inverter is probably dead. You can see if the inverter outputs a good, stable voltage with a multimeter. If you don't own one, just replace it, and if it doesn't solve the problem, you'll have to replace the LCD too.