JVC GRD231US
Service Manual

SECTION 1 PRECAUTIONS
1.1 SAFTY PRECAUTIONS emission. Consequently, when servicing these products, replace the cathode ray tubes and other parts with only the specified parts. Under no circumstances attempt to modify these circuits.Unauthorized modification can increase the high voltage value and cause X-ray emission from the cathode ray tube. (12) Crimp type wire connectorIn such cases as when replacing the power transformer in sets where the connections between the power cord and power trans former primary lead wires are performed using crimp type connectors, if replacing the connectors is unavoidable, in order to prevent safety hazards, perform carefully and precisely according to the following steps. � Connector part number :E03830-001 � Required tool : Connector crimping tool of the proper type which will not damage insulated parts. � Replacement procedure a) Remove the old connector by cutting the wires at a point close to the connector.Important : Do not reuse a connector (discard it). Prior to shipment from the factory, JVC products are strictly inspected to conform with the recognized product safety and electrical codes of the countries in which they are to be sold.However,in order to maintain such compliance, it is equally important to implement the following precautions when a set is being serviced. 1.1.1 Precautions during Servicing (1) Locations requiring special caution are denoted by labels and inscriptions on the cabinet, chassis and certain parts of the product.When performing service, be sure to read and comply with these and other cautionary notices appearing in the operation and service manuals. ) parts

(2) Parts identified by the symbol and shaded ( are critical for safety. Replace only with specified part numbers.

NOTE : Parts in this category also include those specified to comply with X-ray emission standards for products using cathode ray tubes and those specified for compliance with various regulations regarding spurious radiation emission. (3) Fuse replacement caution notice. Caution for continued protection against fire hazard. Replace only with same type and rated fuse(s) as specified. (4) Use specified internal wiring. Note especially: � Wires covered with PVC tubing � Double insulated wires � High voltage leads (5) Use specified insulating materials for hazardous live parts. Note especially: � Insulation Tape � PVC tubing � Spacers � Insulation sheets for transistors � Barrier (6) When replacing AC primary side components (transformers, power cords, noise blocking capacitors, etc.) wrap ends of wires securely about the terminals before soldering.

Fig.1-1-3 b) Strip about 15 mm of the insulation from the ends of the wires. If the wires are stranded, twist the strands to avoid frayed conductors.
15 mm

cut close to connector

Fig.1-1-4 c) Align the lengths of the wires to be connected. Insert the wires fully into the connector.
Metal sleeve

Connector

Fig.1-1-1 (7) Observe that wires do not contact heat producing parts (heatsinks, oxide metal film resistors, fusible resistors, etc.) (8) Check that replaced wires do not contact sharp edged or pointed parts. (9) When a power cord has been replaced, check that 10-15 kg of force in any direction will not loosen it.

Fig.1-1-5 d) As shown in Fig.1-1-6, use the crimping tool to crimp the metal sleeve at the center position. Be sure to crimp fully to the complete closure of the tool.

2.0 5.5

1.25

Crimping tool

Power cord

Fig.1-1-6 e) Check the four points noted in Fig.1-1-7.
Not easily pulled free Crimped at approx. center of metal sleeve

Fig.1-1-2 (10) Also check areas surrounding repaired locations. (11) Products using cathode ray tubes (CRTs)In regard to such products, the cathode ray tubes themselves, the high voltage circuits, and related circuits are specified for compliance with recognized codes pertaining to X-ray

Conductors extended Wire insulation recessed more than 4 mm

Fig.1-1-7 (No.YF042)1-3