Laserjet 4250 will not recognize new official HP 42X cartridge

[Jack1944]

HP 4250n on Mac Mojave recognizes old 42A cartridge, but will not accept brand new official 42X cartridge, HP brand, never refilled.  Shows "Incorrect Supply Installed" warning.  Warning cannot be cleared by connecting to printer via IP address.  No driver update available.  Unable to return cartridge to vendor, but it came in a sealed HP box, not a fake.  Am about to drain toner out of it and put in working 42A cartridge.  Very frustrating to have followed HP instructions, bought an expensive HP new cartridge, and still stymied by cartridge protection methods.

[Jack1944]

UPDATE - On justanswer.com there is a thread saying that the 4250 will not accept 42X high capacity cartridges, and that the error message means that I have real HP product, just not one that will work in a 4250.  If it were fake, it would say "non-HP supply installed".  Can  anyone verify this is correct?  If so, I assume that my problem is that the drivers were never updated to accept the 42X supply, and so I am left with a new but useless HP cartridge and great but useless HP printer.  My bad, I guess, for not reading before buying.

[Repairatrooper]

The 42x cartridge is intended for the 4250 series printer. It will not work in a 4240 printer. Is the firmware on your 4250 up to date?

[Valsimot]

What is the exact message you get on the printer's screen? The 42X toner should work in 4250 as described above.

[Jack1944]

THANK YOU ALL VERY MUCH FOR THE REPLIES TO MY POST!  The badge on the outside of the printer says 4250n, but the software in the printer reports as 4240n.  This has been the case since day 1.  The firmware was 2010, but I just updated to the latest available at the HP site (2015).  This was difficult since the HP instructions for Mac say to use the Terminal Utility, but Mac Terminal no longer supports the FTP command as of High Sierra.  However, an old Mac FTP program (Fetch) was able to FTP the firmware RFU file to the HP, and it rebooted and successfully installed the 2015 firmware (as confirmed on the Config Page).  But, end of story, the 4250n still will not accept the 42X cartridge, saying  "Incorrect Supply Installed".  It still runs fine with the 42A cartridge.

[Repairatrooper]

Did you purchase the printer new or used? If used, the previous owner had a problem and rather than repair it properly the technician installed a different formatter or swapped the plate on the front of the printer. What is the model number that appears on the serial number plate of the printer. Do not post the serial number here, just the product or model number, should be on the back of the printer.

[Jack1944]

The model number on the inside plate and the model number reported on the Config page are the same: Q7785A.  The printer was bought new in about 2008 from an HP dealer.  (It might have needed a replacement JetDirect board early on, I can't remember. The cover plate over the JetDirect Board also says Q7785A.)  It is still the same exact machine we got new and unboxed many years ago.  On the Config Page it says:  "Product Name: hp LaserJet 4240".  On the badge it says "HP LaserJet 4250n".  On the paper tray it says: "HP LaserJet 4250/4350 series accessories".  We always assumed that the 4250 was just a newer variant of the 4240 series and that is why the numbers didnt match up.

[Repairatrooper]

2008 is almost 3 years after these devices were discontinued by HP so there exists the possibility that this was old stock or possibly a refurb unit.

[Jack1944]

I shouldnt have been so hasty with the date we purchased it - all I know is that the Manufactured Date is Dec 2007 - see photo of sticker attached.  Does this help?  Thanks again!

[Repairatrooper]

That is likely one of the last of those produced. I wonder if it was simply a factory error in badging or something underhanded. Either way you are stuck with using low yield cartridges.