Leakage Current Hot Check (See below Figure) Plug the AC cord directly into the AC outlet.ĭo not use a line Isolation Transformer during this check.Ĭonnect 1.5K/10watt resistor in parallel with a 0.15uF capacitor between a known good earth ground (Water Pipe, Conduit, etc.) and the exposed metallic parts. When the exposed metal has no return path to the chassis the reading must be infinite.Īn other abnormality exists that must be corrected before the receiver is returned to the customer. If the exposed metallic part has a return path to the chassis, the measured resistance should be between 1MΩ and 5.2MΩ. Place the AC switch in the on position, connect one lead of ohm-meter to the AC plug prongs tied together and touch other ohm-meter lead in turn to each exposed metallic parts such as antenna terminals, phone jacks, etc. With the instrument AC plug removed from AC source, connect an electrical jumper across the two AC plug prongs. Leakage Current Cold Check(Antenna Cold Check) Keep wires away from high voltage or high temperature parts.īefore returning the receiver to the customer,Īlways perform an AC leakage current check on the exposed metallic parts of the cabinet, such as antennas, terminals, etc., to be sure the set is safe to operate without damage of electrical shock. When replacing a high wattage resistor (Oxide Metal Film Resistor, over 1W), keep the resistor 10mm away from PCB.
MSTAR ISP UTILITY V4.4.3.8 TV
If any fuse (or Fusible Resistor) in this TV receiver is blown, replace it with the specified. It will also protect the receiver and it's components from being damaged by accidental shorts of the circuitry that may be inadvertently introduced during the service operation. Use a transformer of adequate power rating as this protects the technician from accidents resulting in personal injury from electrical shocks. An isolation Transformer should always be used during the servicing of a receiver whose chassis is not isolated from the AC power line.