IMac G4 20inch a1065- blank screen.

IMac G4 20 inch screen is blank but it made a start up chime.

Also HDD wordking and system boots up. I can change a brightness of display, but cant see any picture.

I did a PMU NVRam resets- still the same.

Checked cable on the LCD- secure.

Plese help me if you have any ideas.

Thank you