Hello, A customer gave me a Canon PIXMA MG6450 printer to reset the ink meter. I found no problem handling to enter the service mode. Unfortunately, when I do this procedure (6 times for the MG Series), nothing happens neither on the printer nor on the computer, I think my client tinkering (because he tried to do it himself ( blocked the service mode so I defer to you, do you have the solution? In addition I can run the printer by pressing 4 times instead of 6 but it's temporary, as soon as I turn it off, it's gone for error 5B00. thank you in advance