Printing problems are the source of many calls we receive from clients. Somehow, their printer has stopped working.

This first thing I ask is "Is the printer turned on?" This is sometimes the problem for clients who have ink jet printers. All ink jet printers should be turned off when they are not in use to prevent the ink from drying out and clogging the printer heads. However, in our days of wireless computing, this means you need to go to the printer to turn it on and off each time you print. If you dislike having to turn your printer on and off, consider a laser printer. These are now very reasonably priced.

If the printer is on, and you still cannot print, the printer may have been "stopped" in the printer utility. Each time you press the command to print, a file is sent to the printer. You can check the status of your printer after choosing Command-P by looking in your dock. You will see an icon that probably looks like your printer. As the file is sent, you will see a picture of a sheet of paper:

If there is a problem, you may see the printer jumping up and down in the dock and the icon will have a yellow caution triangle on it:

Click on the icon and you will see a dialog box similar to this one:

Typically, Mac users tend to click the "Stop Job" button.

The dock icon then changes to a red exclamation point and the trouble continues:

Now, each time the user try to print, there is an exclamation point in the printer dialog box, warning the user that there is a problem, but many overlook it.

Now it is time to fix the problem, but just what is going on? Is the printer stopped? Is the printer turned on, or is there some other problem? The easiest way to diagnose a printer problem is to go to the System Preferences application and choose "Print & Fax:

You will then see this box:

It will show you all the printers that have been set up to to work with your computer. Highlight the printer that is giving you problems, then click the minus button (see the red circle). You may see a window that asks if you want to discard spooled printer files. Choose yes.

Now it is time to add the printer back. Click the plus button (see the red circle). The printer will then send out a signal to every printing device that is attached to it, either physically or through a wireless connection and the results will be reported in this screen:

In the above example, you can see that there is no printer that is directly attached to my MacBook Pro. The Brother printer is attached to my AirPort Extreme Base Station and Printer Sharing via Bonjour has been turned on in the AirPort Utility. The Stylus Photo is attached to my iMac, and printer sharing has been turned on in the "Sharing" System Preference. Since the iMac can also "see" the Brother, it reports it as a shared printer.

While it is possible to print and sometimes fix problems, diagnosing a printer problem is much easier when the printer is directly attached to a computer.

The first thing to check is to make sure the printer is turned on. This is also a good time to make sure that the USB or FireWire cable is properly attached at both ends.

Next, make sure the printer is not showing an error message on it's display screen (if it has one).

The first picture is from my Brother Printer. It does not send a message to the computer to tell you that it is out of paper. Instead, it displays the message on its screen. The second picture is from the screen of my Stylus Photo printer. In this case, it is out of ink. Again, unless this computer is directly attached to my computer, I may not see an error message. Instead, the icon in my dock will just stay there with the white document. If I click on the icon, I might see this screen:

Is it Fixed?

These steps will probably fix your printer problem. If you are still having trouble, save your document and then re-start your computer. If it there is still a problem, you may want to contact us at Dr. Mac.

Illustrations are from Mac OS X 10.4.10