Troubleshooting printers

If you do not see the expected output printed, the most likely cause is some type of hardware malfunction. The following troubleshooting procedures may help you to isolate the problem.

For serial printers:

• If the printer uses the XON/XOFF flow control protocol, make certain you specify the non-modem control device for the serial port (such as /dev/tty1a).

• If the printer uses hardware flow control, specify the modem control device (such as /dev/tty1A). You will also need a cable capable of supporting hardware flow control -- see ``Setting up RTS/CTS protocol (hardware flow control) printers''. (For more information on the naming convention for serial ports, see the serial(HW) manual page.)

• A printer that uses XON/XOFF flow control, and that is configured as Data Circuit terminating Equipment (DCE) should require a serial cable with only pins 2, 3, and 7 connected straight through (assuming 25-pin connectors are used).

  See serial(HW) for a description of the pin connections if the printer is configured as Data Terminal Equipment (DTE). This manual page also describes the equivalent 9-pin connections.

• Recheck your printer configuration by verifying the switch positions in the printer manual.
  

• Make certain that the system recognizes your serial port. You can verify this by running the hwconfig(C) command, or by checking the file /usr/adm/messages. If your port is one of the non-intelligent boards supported by the built-in serial driver, you will see a message similar to this:

     %serial 0x03F8-0x03FF 04 - unit=0 type=Standard nports=1
  

  If unit=0 is displayed, the serial port is considered to be COM1. If the unit is 1, the port is considered to be COM2. nports= denotes how many ports the driver recognized on the adapter. If you connect your serial printer to the first port on COM1, the associated device name will be tty1a. The second device on COM1 is tty1b, and so on. Devices on COM2 are named tty2a, tty2b, etc.

  Intelligent serial adapters may display different bootup messages specific to their drivers; they may also use a different scheme for device names. The message displayed in this case may look similar to this:

     %ONBOARD  0x0230-0x023F 34  0 unit=0 mem=0x000D0000 nport=16
  

  Be sure to read the documentation for the adapter and its drivers before attempting to install serial devices such as printers.

• Recheck the switch settings on your serial port. If you are using a multiport adapter, try other lines on that card and be sure it does not conflict with the standard COM ports. Try attaching the printer to a standard serial port, COM1 or COM2, to see if the printer and cabling are functioning correctly.

• Make certain your cable is securely connected.

• Check that no wires in the cable are broken. One way of testing this is to use the cable on another system that is known to be working correctly.

• Recheck your printer configuration by verifying its switch settings in your printer hardware manual.

• Recheck the switch settings on your parallel card. It must also be recognized at bootup. You can verify this by running the hwconfig(C) command, or by checking the file /usr/adm/messages for a message similar to this:

     parallel 0x378-0x37A   07    -    unit=0
  

  unit=0 refers to /dev/lp0, unit=1 refers to /dev/lp1, and so on.

If the card is recognized, an entry will be printed that has similar information to the entry above. The interrupt vector is listed in column 3 (or with ``vec='' for the hwconfig display); make certain that it does not conflict with other hardware.

You can now set up and customize the printer spooling software as described in ``Adding local printers'' and ``Configuring Hewlett-Packard network printers and print services''.