Laptop Acer 7551G shows no picture?

Hello everyone, my Acer Aspire 7551G laptop doesn't display any image. Even when I connect the laptop to an external monitor, no image appears.

The laptop only works via the power cable.

The battery is there but it is not charging and appears to be defective. The laptop boots up, you can hear the fan, the power supply light is blue and the battery light is orange.

Even without the battery in the laptop, no image is displayed.

Is the image not showing because of the defective battery? Or is it the BIOS battery? What else could be causing it?

I'm desperate 😥