I have a fairly new MB5420. It has been rock solid but over the past week it has developed a problem with the black ink not printing properly.Without exaggeration, I must have done 40 head cleanings and 30 deep cleanings and used three different black ink cartridges (all Canon). The pattern shows the black ink is good, but then as soon as I print something, the black ink is immediately a problem again. I'm at wits end and very disappointed. I even tried a Auto Head Ailgnment, no luck. Please advise.
