Acom 1500 Replacement Manual

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Acom 1500 Replacement Manual Manual pdf 1 page image

1ACOM1500 TUBE REPLACEMENTThis step-by-step instruction is about the tube replacement and idling currentsre-adjustment of ACOM1500 power amplifier. Please follow all details closely sincethe work is difficult, with many details to keep track about, and might bedangerous too. Do not hesitate to contact your local dealer or nearest ACOM'sservice for any advice. Please don't attempt tube replacement by yourself, if youdon't feel comfortable with repairs!SAFETY FIRST!W A R N I N G HIGH VOLTAGE!===========================The amplifier works with high voltages up to 3000V which is LETHAL! For yoursafety pull the amplifier power plug out of the mains wall outlet and WAIT ATLEAST 30minutes EACH TIME BEFORE you remove the cover of the amplifier. Disconnectall cables from the amplifier (grounding last). Do not touch any part inside whilethe amplifier is open because some residual voltages may still be present!1. Removing the top cover.Using a Philips-2 screwdriver, unscrew 9 pcs of "eco-fix" flange-button headscrews to release the top cover (2x3 pcs on each bottom-side edge, and three moreon the rear-top edge of the box).Lift the rear edge of the cover slightly (to 2-3cm) and then pull the coverbackwards, in order to release it from front-panel's chutes. Remove the top cover.2. Discharging HV capacitors.You will see inside:- the MAINS PCB that is mounted on an aluminum sub-chassis, just above the big HVtransformer;- the HV rectifier PCB in front of the MAINS PCB (with four big diodes, one wire-wound resistor, and one disc ceramic capacitor on it);- the HV filter PCB, located just below the HV rectifier (with 8 electrolyticcapacitors on it).