DesignJet Z9 Printhead Seating Error

[DJ-Z9_User]

Here is my problem - New Printheads (1 & 2) which have just been installed due to requirements to “Replace” them (after multiple attempts to clean the old Printheads have failed - despite almost 0 usage on those initial PHs - although these original PHs have just Expired).  Unfortunately new Printhead 1 is showing "Replacement Incomplete" & PH 2 shows "Reseat" despite multiple attempts to both clean the PHs and the Control Strip and Reseat them).  

I purchased this printer used, but in fairly clean condition.  I saw the Reply to a similar question posted on 12/24/24 by Repairatrooper about getting the Printer to recognize new PHs and checking the cleanliness of the Left Spittoon.  My foam squares appear reasonably clean, but I would be willing to disassemble the unit to clean them if that truly would help the situation, unfortunately no details were given as to the process of cleaning them.  I have access to a Service Manual so presumably could get to these pads for cleaning, but no details were given about this.  For instance, Do I remove them to clean them? In what manner can they be safely cleaned?  And most importantly if it turns out performing this cleaning does not solve this seating issue then what comes next - Is there a way to test the Control Strip that connects to the Printheads? - I see no obvious cracks in the Control Strip or other issues.

[Repairatrooper]

The issue is built up ink prevents the printheads from purging the carrier fluid they are shipped with. HP does not have instructions on cleaning the pads, they are typically replaced. I have in situations where a user absolutely needed to print, wiped all the ink off the left pads and that worked the time I tried it. The real problem is really only the top pad that gets polluted. There is only one screw on the top of the spittoon holding the top pad in place. Easily reached without any disassembly required. Be sure you also have current firmware installed as they have made changes to reduce ink build up.