HP Laserjet 2420

Overall Printer Test

Performing these tests will weed out some of the most common problems with this type of printer. I'll be testing an HP 2420 printer with added JetDirect card for feeding, print quality and network connectivity issues. I will also cover how to resolve some of the issues that might arise.

Error Message On Startup

Turn on the printer and you'll see this right away. There are a number of reasons for an error message right when you turn on the printer. If you get an error message, you'll just have to google it and hope it's an easily replaceable part in the printer. The error could also be a jam that already exists in the printer, so search around and see if there's any paper crammed in there. Other simple errors could be that there's no paper or if you forgot to put a toner in. But, if anything comes up that seems strange, just google it and find out what's broken and if it's worth fixing. An example is a 57.03 error. For this particular model it means a fan failure inside the printer.

Printer Gear Test

Just turning it on will do the trick here. The printer is generally a little noisy and gets louder as it gets more usage. I'm not talking about a little usage, but EXTENSIVE usage. As the printer starts up, listen for signs of grinding gears on the inside of the printer. It's common for the printer to be noisy, but grinding and slipping gears can be two possible issues:

1. The gears on the inside of the printer could be worn down and need to be replaced. You get gear "packs" on the internet if you look around. Maybe I'll post a link sometime if I come across one.

2. The fuser does not turn easily anymore. This puts more pressure on the gears causing them to slip. This can also cause the issue of the worn gears. Completely replacing the fuser is your best bet here.

3. A little of both 1 and 2. If you replace the fuser, just replace the gears too, and it should run nice and quiet after that.

Print Quality/Feed Test

If the printer sounds OK and there aren't any error messages, then it's time to test the rollers/fuser by printing out some test pages. I always like to go to the information menu and print the menu map. This usually prints out about 3 pages and takes very little effort. You can do it a couple of times while still printing and queue them up to get a better test to see if the printer doesn't have any intermittent feed/fuser issues. When there are problems with the print quality, it's usually the fuser, or more specifically, the fuser sleeve. When there are issues with feeding the paper, it's usually just the pickup rollers. I won't be discussing the manual feed tray in this test since it's very error prone and isn't worth the hassle.

• If you hear a clicking noise every couple of seconds and then an error stating there's a paper jam, it's probably just the printer trying to feed in paper and failing because the roller is sliding on the paper and not sticking to it properly. This can be fixed by replacing or cleaning the rollers. Cleaning the rollers can potentially get you a lot more life out of your rollers, but it can also be a very short lived fix. If that's the case, replacing the rollers will fix this issue.

• If, after the paper feeds in successfully, you have black smudges that seem to have a vertical pattern, it's likely the fuser sleeve is shot. In the fuser, the component that makes the toner stick to the paper, there is a sleeve around one of the roller type components that can go bad. When it goes bad, the toner sticks to it and fuses toner to places on the page where it's not supposed to. Replacing the fuser sleeve will fix this issue.

Network Connectivity

The HP LaserJet 2420 has a model that comes with a builtin ethernet port. If you're lucky enough to have this model, you can just plug in a network cable and configure it for your network. If not, you're not totally out of luck. These printers come with an EIO expansion port. You can usually find a good JetDirect card that fits into this port for pretty cheap. Either way, the reason I'm mentioning network connectivity at this stage of the game is because of how vague the resets are for this printer. If you are using a JetDirect card for connectivity, a simple "Restore To Factory Default Settings" in the "Resets" menu in the printer will not reset the JetDirect card settings. I don't know if it will reset onboard network settings, but I KNOW it won't do it for the JetDirect card. It took me a while to figure out what the heck was going on when I would reset the printer and still the old hostname from the previous user was hard coded in the settings.

Cold Reset - The ACTUAL Method Of Getting Factory Defaults

I found this little gem after searching around for about 10 minutes (an eternity!) on the internet. This type of reset is not in the menu and will actually reset the JetDirect card settings as well to their defaults. This is the simplest way to start working with any used network component. There are usually a TON of possible network settings and starting over is usually easier than manipulating an unknown existing config. There is also settings corruption that can occur. This is when the settings you choose have somehow been corrupted so resetting to factory settings will rewrite all the settings over again potentially solving issues with the device. Here are the steps to do a Cold Reset.

1. Make sure the printer is powered off and the network cable is unplugged (not required, but suggested to prevent duplicate IPs on your network).

2. Turn on the printer and you will see the memory check start where it cycles through each MB of memory. While this number is quickly increasing to the max number of MB of RAM, press and hold the green "check mark" button.

3. When all three lights are lit and solid let go of the button.

4. Use the arrow keys to scroll down to the "Cold Reset" option and select it using the "check mark" button again.

5. The printer will do a bunch of stuff on the screen, but in the end, it will have a message like "press the stop button to get to ready status" or something like that. Once you do that, the printer is ready to be used.

6. At this point it makes sense to set your network settings. I usually choose DHCP and leave the default hostname (I know it will be unique since it's based on the JetDirect card serial number) just because of my network setup.

7. Power off the printer.

8. Plug in the network cable.

9. Turn it back on.

10. Now you should be able to communicate with the printer on your network.

Service Manual

In case you can't find this anywhere else, you can download it from here. Enjoy!

HP LaserJet 2420/2410 Service Manual

Conclusion

The HP LaserJet 2420 is an overall solid printer that can last a very long time if you can keep replacing the parts that get the most wear and tear.