Top case keyboard / trackpad and power button not working

Hello,

On a Macbook 4,1 (A1181) the keyboard, trackpad and power button are not functioning.

I manage to power on the computer from the motherboard and it is functioning fine, using an external usb keyboard and mouse. The main concern is the power button.

Will a silver ribbon replacement solve the above issues, does it needs a complete top case replacement?

Just a side note, not sure if it matters, but the laptop is working only from the power source since the battery is completely dead.

Thank you