HP MFP M428fdn scanner problem

[lebo]

Machine displays "Scanner problem" Unable to scan or copy, Turn off/On , if the problem persist, contact HP service.
Scanner moves to home postition after initialization, (doesnt light up) Printing is possible.
Information menu (Assert history) displays error code 0x02cef78b but I do not know what is it and if it relates to the described problem.
Thank you for help.

[tmw]

If you look up the error it might narrow something down, but more then likely you would need to replace the entire adf bed. HP doesn't offer individual parts for it.

[tmw]

Or it could be a formatter at fault.