Servisnij Rezhim Shassi Mc 049b
Contents.......2 Safety Precauti ons......3 Control Descriptions......4 Specifications.......7 Adjustment Instructions.....8 T rouble Shooting.....12 Printed cir cuit board.....16 Block Diagram......18 Exploded Vie w......20 Exploded Vie w Parts List.....21 Replacement Parts List..... During the servicing of a receiver whose chassis is not isolated from the AC power line. Use a transformer of adequate power rating as this protects the technician from accidents resulting in personal injury from electrical shocks. 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. If any fuse (or Fusible Resistor) in this TV receiver is blown, replace it with the specified.
Insulating, Connecting and Protecting in the Low and Medium Voltage field with innovative, complete system solutions: from top-quality products, over competent advice to superior training courses. Chertezh korpusa dlya sabvufera 10dyujmov.
When replacing a high wattage resistor (Oxide Metal Film Resistor, over 1W), keep the resistor 10mm away from PCB. Keep wires away from high voltage or high temperature parts. Due to high vacuum and large surface area of picture tube, extreme care should be used in.
With the instrument AC plug removed from AC source, connect an electrical jumper across the two AC plug prongs. 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. If the exposed metallic part has a return path to the chassis, the measured resistance should be between 1MΩ and 5.2MΩ.
When the exposed metal has no return path to the chassis the reading must be infinite. An other abnormality exists that must be corrected before the receiver is returned to the customer. Connect 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. Measure the AC voltage across the resistor using AC voltmeter with 1000 ohms/volt or more sensitivity. Reverse plug the AC cord into the AC outlet and repeat AC voltage measurements for each exposed metallic part. Any voltage measured must not exceed 0.75 volt RMS which is corresponds to 0.5mA.
In case any measurement is out of the limits specified, there is possibility of shock hazard and the set must be checked and repaired before it is returned to the customer.