This Power SW Aj7201B is suitable for Roland RA-640 printers. This is the original Roland part (number 13129170).
 
Printer compatibility
Roland AJ-1000
Roland AJ-1000i
Roland BN-20
Roland CJ-400
Roland CJ-500
Roland CJ-540
Roland CJ-60
Roland CJ-70
Roland CM-12
Roland CM-24
Roland CM-300
Roland CM-400
Roland CM-500
Roland CS-20
Roland CX-12
Roland CX-24
Roland CX-300
Roland CX-400
Roland CX-500
Roland FJ-40
Roland FJ-400
Roland FJ-42
Roland FJ-50
Roland FJ-500
Roland FJ-52
Roland FJ-540
Roland FJ-600
Roland FP-740
Roland GX-300
Roland GX-400
Roland GX-500
Roland GX-640
Roland LEF-12
Roland LEF-20
Roland PC-50
Roland PC-60
Roland PC-600
Roland PNC-1860
Roland RA-640
Roland RE-640
Roland RF-640
Roland RF-640a
Roland RS-540
Roland RS-640
Roland SC-500
Roland SC-540
Roland SC-545ex
Roland SJ-500
Roland SJ-540
Roland SJ-600
Roland SJ-640
Roland SJ-645ex
Roland SJ-740
Roland SJ-745ex
Roland SP-300
Roland SP-300i
Roland SP-300v
Roland SP-540i
Roland SP-540v
Roland VP-300i
Roland VP-540
Roland VP-540i
Roland VS-300
Roland VS-300i
Roland VS-420
Roland VS-540
Roland VS-540i
Roland VS-640
Roland VS-640i
Roland VP-300