icom_hm56-56a_capreplace

ICOMTechnical BulletinAmateur DivisionAM-081904-EU11HM56/56AElectrolytic Capacitor replacementA common failure of the HM56/56A microphone,causing the radio to remain in TXmode when the mic is connected,is failure of the electrolytic capacitors on the micro-phone circuit board.Generally,replacing all 5 capacitors on the board repairs the prob-lem and allows the microphone to work properly again.This repair is not a guarantee,simply a common failure point and reference for repair.The 5 capacitors on the board are labeled as C3,C4,C7,C13 and C14.They can beordered from the Icom parts department using the following part numbers:C3,22mf16v(4510004430)C7.0.1mf50v(4510005950)C3.22mf16v(4510004430)C14,1mf50v(4510004440)C13,1mf50vIcom America Tech support(4510004440)8/19/04