Roland VersaUV LEJ-640 Service Notes page 147

Put the black probe into CN204-8pin on the DC Junction
14
Board and the red probe into CN204-2pin (for SW supply
27V(A)) or CN204-4pin (for SW supply 27V(B)) to confirm
that output voltage value is +27V+0.1.
SW supply 27V (A)
SW supply 27V (B)
Confirm that the opposite connector of the cable
connected to CN204 is not connected.
Turn off the main power SW.
15
Disconnect the special tool cable.
16
And connect the connector of the CN1001 on the AC Junc-
tion Board and CN2 on the SW supply (5V).
Probe
< Rear side >
Main power
CN2
SW Power supply (5V)
3-73
8 pin
2 pin
Probe
8 pin
4 pin
Special tool cable
CN1001
AC Junction Board