nice completed SERVICE MANUAL as the description THANK YOU !!!-
Text excerpt from page 4 (click to view)
KDC-5021/5021V,506
COMPONENT DESCRIPTION
SWITCH UNIT (X16-167x-xx)
REF. No. IC1 IC2 Q1 Q2 Q3 Q4 FUNCTION LCD DRIVER REMOTE CONTROLLER KEY SCAN START IC2 POWER SUPPLY SW KEY GREEN ILLUMI SW KEY RED ILLUMI SW OPERATION Drives LCD. Controls the unit. Turns on when the base level goes "L". Turns on when the base level goes "L". Turns on when the base level goes "H". Turns on when the base level goes "H".