DC input jack broken.

Is there two models of the HP Pavillian zd7000 as some of the instructions and photo's differ to mine? For instance, Ram cover needs removing to allow access for screen wire removal. Also the top fan is connected to the heat sink frame and has to be removed before not left in place until later in the process.

When all instructions and screw removal is complete the keyboard is firmly fixed on the drawer side but no screws are visible!

I am trying to replace the DC input jack as it has an intermittent connection. The AC DC converter shows a steady 18.6v of output.