HP OfficeJet Pro 7740 prints test page, but won't print anything from MacOS 10.15.5

[jskelton]

Problem: ANY print job (including Print Test Page from printer queue) sent from either of two Macs (both running 10.15.5) results in: printer recognizes job incoming, shows circle icon/"Printing" but stalls there, never completes job (even allowed to sit 12+ hrs). Computer shows job still in queue during this symptom. Cancelling job on either computer or via printer control panel clears the job on both devices and they revert to normal. 

Printer's internal test print comes out fine. 

Printing worked until two days ago. Since last successful print, no changes to printer or computer software occurred as far as we know. Connecting via WiFi, have not tried USB. 

Non-HP color cartridges installed, and their ink level is not registering properly, but color prints on test print. 

Tried the following without change to symptoms:

• rebooting both devices
• resetting MacOS print system - which includes reconnecting to printer
• changing drivers - used Secure AirPrint, AirPrint, 7740 Series - no difference
• pulled out all hair on my head

TIA!

[jskelton · Accepted solution]

Replaced the color cartridges with new HP-branded cartridges.

Problem resolved.

Imagine that.