Epson Equity 286 PLUS - Manual (Page 216)

Note
When you are finished running any of these tests on the test
diskette, you must reformat it using the MS-DOS FORMAT
command before you can use it with MS-DOS.
You see the following prompt before the program performs a test:
Diskette drive (A/B) ?
If necessary, type the drive identifier and press Enter. (If you
have only one diskette drive, drive A is already entered for you.)
Press Y and
Enter at the Proceed prompt to begin the test.
Press N and Enter to make corrections.
Note
Be sure to insert a blank diskette that has been formatted
using the MS-DOS FORMAT command before you run the
Diskette format test. Then use that diskette when you run any
of the other destructive tests. Check that you have inserted
the correct diskette before you enter
Y at the Proceed
prompt.
Floppy Disk Error Messages
The diagnostics program displays two types of error messages
while testing a diskette drive: messages the program generates
and those the controller generates.
The program may display the following error message during the
Disk change line test:
Warning - Change line inoperational
This message appears if the line is not working properly and may
indicate a problem in the drive or its controller.
C-22 Performing System Diagnostics