Pagewide MFP P77760Z streaks

[copyman]

I posted about this machine in another thread. It sat for a few years because of wrong inks according to customer. So it's brand new, I was able to get the right inks online and got it working. It went through some type of initial setup, etc. It's working good except black has streaks. Other color test pages fine. I tried several of the print head & other cleaning procedures in the service mode. Helped some but a few streaks still there. Mostly shows on solid fills.

Maybe black print head clogged? Because of wrong inks I don't think machine ever did initial setup so no ink should of been in the printheads to clog but I don't know this model? Never seen one before. Weird no fans and real quiet.

Have the service manual and see how to remove the print head, can this be cleaned?

I saw an advanced printhead maintenance kit online. Will this help clean the black PH without having to take it out?

Any ideas to get black from streaking would be greatly appreciated.

Thanks in advance

[Cipher]

Apart from the manual cleaning procedures these print head(s) pretty much look after themselves.
All you can really do is print off a bunch of full coverage black prints and hope the nozzles unclog.

More than that it's a print engine assembly replacement.
Which is expensive if it's not covered under the warranty period.

I took one out during training, but I've not had to replace one in the field (yet).

The advanced printhead maintenance kit is A4R piece of card with raised felt in the middle to physically scub the printhead.
But I think that's only meant for the smaller A4 Pagewide's.