Screen flickers, then turns black after periods of increased heat.

SYMPTOMS:

1. Screen flickers than goes black. LCD still shows image, but no backlight.

2. Hot temperatures (145+ degrees) seem to trigger the shutoff.

3. A vertical column about 4 inches wide in the middle of the LCD is dimmer than the rest of the LCD.

4. Moving the screen affects the flicker negatively.

5. History of logic board issues.

6. Computer regularly runs hot.

What could this problem be? Is it the inverter cable? A lamp burnout? Do I need to replace the entire screen?