Film + error lights flash. I have replaced the ink

This indicates that either the black print cartridge is faulty, misplaced or missing. Try inserting a different black cartridge. Also firmly press the large green plunger fully down once, and then release it. The plunger should return to its original position. Then reset the printer and try printing again. If the problem persists try using a new black cartridge and primeit before use with the power on.

This error code gives an indication that one of the cartridges are either faulty, misplaced or completely missing. Also it can indicate that the cartridges are all misplaced, making a bad contact or of a wrong cartridge model. The first step you should take is to replace the black cartridge. See that the Black Cartridge passes the test on account that it is not malfunctioning, misplaced or of wrong type. If it passes, I would suspect a malfunctioning Trailer Cable.
OK, I assume you have changed the Black Cartridge with same error results. The next test you should take is that try sending a plot wider that 36 or 24 inch ( as per the model's width { as some are of 36" and others are of 24" } ) and see that the second side is printing out fine with not problem. If yes, the black cartridge is the culprit and replacing has solved it. But if you see that the printer is flashing the ready light but not plotting then something is wrong with the Printing Parallel Port Mode. For this point only, make sure that the Printer Parallel Mode is correctly set into ECP on the PC BIOS.
Replace the Printer Cable which is not longer that 2.5 - 3.5 meters. The other point you can do is to check that the Printer Driver is up-to-date. You can check at www.designjet.hp.com.
Also try the self-tests. They are the Setup - test or the Demo - plot. If they are reported OK, then surely this is a Faulty Cable Issue.
Sir, I think now you can get it. Please reply me with your view.
Thank you Sir, Have a nice day.