Yamaha Bass Amplifier service manual Circuit Boards, F-20B

Contents BASS AMPLIFIER CONTENTSIMPORTANT NOTICE FOR THE UNITED KINGDOM F-20BWARNING CHEMICAL CONTENT NOTICE IMPORTANT NOTICEPANEL LAYOUT SPECIFICATIONSF-20B POWER TRANSFORMER BLOCK DIAGRAMCIRCUIT BOARD LAYOUT POWER AMPF-20B DISASSEMBLY PROCEDURE1.Pre-MainUnit Time required about 2 min 2.Speaker Time required about 2 minF-20B 4.MAIN 2/2 Circuit Board 5.Power Transformer Time required about 4 minTime required about 3 min F-20B CIRCUIT BOARDSINSPECTIONS IC BLOCK DIAGRAM2.Power supply 3.Inspection procedureF-20B CONTENSPARTS LIST BASS AMPLIFIER20 Pre-MainUnit OVERALL ASSEMBLY10 Overall Cabinet Assembly F-20BNew parts F-20BDESCRIPTION REMARKSPRE-MAINUNIT V 6 9 5 4 8 0 0 Chassis F-20BF-20B ELECTRICAL PARTSHF456330 F-20B5 F-20B OVERALL CIRCUIT DIAGRAMABCDEFG P.1 F-20B