Marantz PM-15S1 Service Manual page 20

12. The Main microprocessor (QU01) has been Update.
13. Turn off Power switch, then disconnect FFC cable from
PM-15S1.
14. Check the version number of the fi rmware
Refer to "4. SERVICE MODE" on page 3.
12.
13. PM-15S1
14. VERSION
3 "4. SERVICE MODE"
18
FFC