nozzle clogged

I have a G3501 that does not see high volume use. I use original Canon ink. There are some issues on the nozzle check print-out: I have tried the built-in cleaning and also done manual cleaning as follows: I let the black print head sit in an alcohol/distilled water mix overnight and then...

Hello dear memebrs. After about 3 years i opened up my mp 540,reconnected the disconnected pgbk pipe and started testing nozzles.as you guessed,there were some clogged nozzles after these years,so i took the head under direct water pressure and waited a night to reinstall.the results were good...