IBM 5155 Manual To Operations page 164

16
Your printer also is controlled by program
commands from the system unit. If you are still
having a printer problem, or if you have a printer
problem only during a particular program,
examine the program thoroughly for commands
that might cause the printer to produce
r--,
undesired results. If you have completed the
printer self-test and have no apparent program
problems, have the unit that the printer is
attached to serviced.
8000-8 Test January 1984