Scanner imaging fault. Advice please.

When scanning with the Canon Lide 110, there is a 3cm black band down one side. It appears to be about 1/8th of the platen width.

Canon Lide 110 Sample image

I have carefully dismantled the unit. I have checked and re-seated the ribbon cables. I have closely inspected the scanning head and checked electrical continuity between the head and the integrated circuit board in the base of the machine via the ribbon. Everything looks perfect, and the light bar looks normal in operation.

I am assuming this is a fatal hardware problem? And advice to the contrary, much appreciated.