IBM PCjr Hardware Maintenance And Service page 137

The diskette may be bad or write-protected.
Repeat the test using a known good 5-1/4 inch diskette
that is not write-protected.
DO YOU HAVE " * " UNDER THE
DISKETTE-DRIVE SYMBOL?
The problem has been corrected. Repeat
advanced POST and the advanced tests to
ensure that the IBM VCjr is operating
correctly.
Diskette Drive 3-600-7