print head warning poor print quality

[jus333]

hp 500 designjet 

print head warning poor print quality

and i replace all of the and three  are showing poor quality printheads

[NC77]

Does printer perform a successful printhead alignment?  Will printer print?

Refer to this support note HP DesignJet 500, 510 and 800 Printers - HP 11 Printhead Errors | HP® Customer Support.

I am a HP forum volunteer.  I do not represent HP.

[jus333]

it goes thru the process but still says poor ink quality

these are new printer heads

[NC77]

Check your printer firmware version.  Should be visible in one of the Control panel menus. It has to be version A.05.01 or higher.  If not, new printheads will error out.  It has been a while since I have run into this issue.  The only way to upgrade firmware is via a USB connection.  Sometimes, these old DJ 500 formatters will not accept the firmware.  The next option is replacing the formatter.  My previous company purchased formatters from Ebay.  We had a trusted source that confirmed A.05.01 version.  Good luck. 

[Repairatrooper]

Are we dealing with OEM or third party supplies. It is possible you have air in the ink lines which will cause issues. Purging the system is really the only cure if that is the problem.