Retro page on dual scan on C458 is faded

[Paolo1970]

On some machines in the field, it happens occasionally that when doing double-sided scans, the odd page (front) comes out perfect while all the even pages (back) come out faded.
Turning it off and waiting about twenty seconds before turning it back on makes the problem disappear and then maybe come back after a few weeks.
Has this happened to you and do you have a definitive solution?

Thanksss

[Synthohol]

try to clean the white reference sheet on the brush roller shaft really well. the CIS knows thats pure white so it will try to reproduce anything darker but if its dirty than dark is already a starting point and it wont pick up 100% density and wind up with light copies.

[tsbservice]

Sample please.
What you did/attempted to resolve this instead of turning off?

[Paolo1970]

Sample please.
What you did/attempted to resolve this instead of turning off?

This Is a sample
I try to update firmware and After change df board but some times the problem appear again.

[Paolo1970]

Sorry..this Is sample

[kingarthur]

have you updated the FW - always do this before anything else

[Paolo1970]

Yes, i update the firmware like a First operation but not solved

[davel]

Both the front and back look like shit

[Paolo1970]

No only the back ..the front Pages are write in pen , the back are two Pages with document