Roland VersaEXPRESS RF-640 Service Notes page 92

Fix the Right Top Cover.
21
Move the Head carriage by hand to the lock position.
22
Turn on the Main Power SW, and then turn on the Sub Power
23
SW while pressing the left, right and down keys to enter the
Service Mode.
Perform [SERVICE MENU]>[SUB MENU]>[CHOKE CL.]>
24
[START].
ON
SERVICE MENU
SUB MENU
SUB MENU
CHOKE CL.
CHOKE CL.
START
3-18
Right Top Cover
Right Top Cover
+
[ ]
[ ]
ENTER