Epson LT-286 - Manual (Page 143)

Before any checks are performed, the program determines the
number of diskette (floppy disk) drives installed in your computer.
If you have two drives, you see this prompt each time you select a
test:
Check which drive (A/B)?
Press A or B and then Enter.
If any errors occur, write down the error code and message and
contact your Epson dealer. Always have diskette drives serviced by
your dealer.
When you finish running the checks, press 0 and Enter to return to
the DEVICE LIST menu.
Sequential Seek Check
This test checks the ability of the read/write heads to locate any
part of the diskette. This action by a read/write head is called a
seek. During this test, each head seeks sequentially from the
innermost track to the outermost track. The innermost track is 39
for a 360KB 5 1/4-inch diskette and 79 for a 3 1/2-inch diskette or a
1.2MB 5 1/4-inch diskette.
Select option 1 from the menu to start this test. The program
displays the number of each track it finds, counting down from 79
or 39 to 0.
The seek is performed by each head, so you see the count twice. If
no errors occur, the menu reappears.
Random Seek Check
This test is identical to the sequential seek check, except that the
seek operation is performed on each track in random order instead
of sequentially. Select option 2 from the menu to start this test.
D-18 Performing System Diagnostics