First you have check your power supply voltage.
Problem symptoms.
There is 12 volts missing due to the IC short.
Use soldering paste.
IC will not detach until  pull over from bottom.
Soldering
Clean up
Now 12 volts are present.
Backlight signal voltage.
Check LED polarity part by part.
This inverter is useful.
DC to DC voltage regulator converter.
Inverter input 19 volt supply.
Control output voltage.
Do the adjust 12 volt.
Now everything ok......
