Epson I+ - Manual (Page 134)

Floppy Disk Drive Seek Check
The computer checks its floppy disk drives by searching the rend/write
heads for any malfunction.
If any seek errors are found, you see this message:
601-Diskette error
If this error occurs, confirm that the system diskette is inserted into drive A.
If this number still appears after you insert the diskette, you may then want
to run the System diagnostics and select option 6 from the DEVICE LIST If
the error persists, consult your dealer about having the drive repaired.
B-3