The HP Officejet Pro printer is a fairly reliable printer, but it has a problem regarding the printer’s ink system. But don’t worry! An ink system failure is less severe than you might think. It’s a pretty easy problem to fix.

How to unclog

Each printer model has its own method of unclogging the printhead, depending on which cartridge you use. The 951 XL cartridge, for example, has a built-in bladder, so the best way to unclog it is to blow air into that bladder.

These cartridges have a few holes in them. The top one is the air hole, so when you tell your printer to do a second or third cleaning, it blows air into that hole. It will also send an electronic signal to the printhead’s nozzles to check their conductivity.

If this signal detects that the nozzle is still dry, you’ll receive a message saying you have a bad cartridge. This will cause the printer to lock the serial number for the cartridge. One thing to note is that if you buy a third-party cartridge, there’s a chance it won’t have the air bladder.

No air bladder?

When the cartridges have no air bladder and just an open hole, nothing will happen when the printer blows air into the holes. If the printhead gets clogged with this cartridge and you try a second-level cleaning, it won’t do anything.

The solution is simple. Insert a new cartridge into the printer and either print a page or do a scan with it. This will cause your printer to unlock itself and forget that it’s supposed to lock the serial number from the “bad” cartridge.

Now you can put the first cartridge (the one the printer labeled bad) back into the printer. You’ll get one final error message claiming that it’s a non-HP cartridge, but you can just click okay on that. You should now be able to print to your heart’s content. For a video walkthrough of this process, click here: HP Officejet Pro Ink System Failure.

0:16 - The Cause

1:17 - “Bad” cartridge

2:04 - The Solution