You might find a printer that is idle, even though it has print requests queued to it.
A printer might seem idle when it should not be for one of the following reasons:
The current print request is being filtered.
The printer has a fault.
Networking problems might be interrupting the printing process.
Slow print filters run in the background to avoid tying up the printer. A print request that requires filtering will not print until it has been filtered.
When the LP print service detects a fault, printing resumes automatically, but not immediately. The LP print service waits about five minutes before trying again, and continues trying until a request is printed successfully. You can force a retry immediately by enabling the printer.
When printing files over a network, you might encounter the following types of problems:
Requests sent to print servers might back up in the client system (local) queue.
Requests sent to print servers might back up in the print server (remote) queue.
Print requests submitted to a print server might back up in the client system queue for the following reasons:
The print server is down.
The printer is disabled on the print server.
The network between the print client and print server is down.
Underlying network software was not set up properly.
While you are tracking the source of the problem, you should stop new requests from being added to the queue. See How to Accept or Reject Print Requests for a Printer for more information.
If print requests back up in the print server queue, the printer has probably been disabled. When a printer is accepting requests, but not processing them, the requests are queued to print. Unless there is a further problem, once the printer is enabled, the print requests in the queue should print.