5-26 888-2595-001 12/20/11WARNING: Disconnect primary power prior to servicing.Section 5 Maintenance and Alignments ZX SeriesSTEP 5 Adjust REV APC LIMIT potentiometer in each PA chassis until redREVERSE FOLDBACK alarm just lights on controller board.STEP 6 Restore all connections to original positions when finished.STEP 7 Procedure complete.5.4.9 Periodic Cleaning and InspectionThe ZX amplifier chassis should be periodically opened, inspected for dust buildup, andcleaned. This inspection should also check for signs of progressive damage, such ascracking cables or evidence of heat stress/burning. In the case of a single amplifierchassis transmitter (ZX2500 / ZX3750 / ZX5000), the transmitter must be switched offand mains power removed to perform safely many of the steps given below. In the caseor larger model transmitters (ZX7.5 / ZX10), one PA chassis may be shut down andserviced while the other continues transmitting. Please consult the section 5.4.10 for aprocedure to follow to safely service one PA chassis at a time.Tools required:Workshop lightVacuum cleaner with hose & nozzle attachmentsHex key set or screwdriver set for tightening mains connectionsSTEP 1 While transmitter is still operating at full power, inspect all externaltransmission line sections for localized discolorations or “hot spots” thatare warm/hot to the touch.a. If localized heating is found, switch off transmitter, open transmis-sion line, and inspect for loose bullets (anchor connectors), split bul-lets, contaminations, or other irregularities.STEP 2 Press front panel OFF button to switch transmitter off.STEP 3 Remove all AC mains power to transmitter, including exciter(s).STEP 4 Take steps to ensure AC mains connection is securely locked out andinadvertent mains re-application is not possible while maintenance isbeing performed.STEP 5 Open all mains access panels and inspect all mains connections fortightness, corrosion, or signs of localized burning.STEP 6 Open transmitter front door and locate hex key in holder to right of PAmodules.STEP 7 Use hex key to open amplifier chassis rear door.
