Imac G4 20 Inch display issues, inverter maybe?

[GrandFraganator]

I have been given a 20Inch Imac G4, its very nice.
But there is no display on the screen, I have shone a torch on it and can not see a image when booted up, However I can see the backing light.
Plugging in an external screen works fine so the logic board should be fine (As far as I know)
I have been able to load the install disk to 10.3 using the external screen.
Im only asking because when I search it seems that normally if its a dead inverter there is no backing light on the screen but there is a image but I have the opposite.

Any advise would be greatly appreciated.
Thanks guys - Jeremy

 

[Stretch]

There might be a loose connection on the display, or the display might be gone.

 

[GrandFraganator]

Thanks for your quick reply
Do you think that having the backing light on the screen rules out the inverter?
Ill try to open it up and see if I can move the connections around.

 

[GrandFraganator]

I took apart and put back together all of the connections from the motherboard to the neck of the computer.
It didn't change anything.
There is a component on the motherboard that makes some weird sounds after boot up and the back light is on for a little bit. I made a short video of this and showing the screens backing light going out as I turn off the computer.
YouTube - Imac G4 20 inch no display and emmiting noise