IBM PCjr Manual page 165

4 Are you using the IBM PCyr
Keyboard Cord to connect your IBM
PCyr Keyboard to your IBM PCyr?
YES - Check the Connectors on
the IBM VCjr Keyboard
Cord to be sure that they
are not bent or broken, also
make sure that the
connectors are pushed all
the way into the IBM VCjr,
and keyboard. Go to Step
5.
NO - Check your IBM PCyr
Keyboard to be sure that
the batteries are good, and
that the Keyboard is
positioned within 6.1
meters (20 feet) of your
IBM VCjr. Make sure
nothing is blocking the
beam between the
keyboard and the front of
thelBMPCy/-. Go to Step
5.
Running the IBM PC/> Tests 6-23