HP-UX System Administrator's Guide: Configuration Management

If the problem is an application program that’s looping or not functioning properly,
try pressing the Break key and then try the intr signal (usually Ctrl-C) or the
quit signal (usually Ctrl-\) to see if you can get a shell prompt back. To find out
what the intr or quit signal is for the affected terminal, go to a working terminal
and enter the command:
# stty -a < /dev/terminal-device
For example:
# stty -a < /dev/ttyp1
NOTE: The stty command, above, should only be used with device file names
for currently active terminal device files (use the who -R command to see which
device files are active). If you attempt to execute stty with a nonactive tty device
file, the command may hang, waiting for input. Press Ctrl-C to abort it.
4. Reset the terminal.
The terminal itself may be stuck in an unusable state. Try resetting it. Consult your
terminal owners document for information on how to do this. Powering the
terminal off, waiting for a few seconds and powering it back on will also reset the
terminal.
NOTE: Power cycling a terminal can have the same effect as sending a BREAK,
which can make the host think it got a BREAK and change the baud rate. If this
happens a lot, use a gettydefs entry that does not cycle through baud rates.
5. Check the terminal configuration.
The terminal may not be configured correctly. You should verify the following:
• Is the terminal in Remote * mode? It should be.
• Is Block * mode turned ON? It should not be.
• Is Line * mode turned ON? It should not be.
• Is Modify * mode turned ON? It should not be.
6. Check the physical connection.
Check to make sure that:
• All cables are firmly attached and in their proper locations.
• All interface cards are firmly seated in their slots.
• The power cord to the terminal is firmly connected.
• The power switch is turned on.
Troubleshooting Terminals 147