Denon DVD-1720/556 Service Manual

Also see for DVD-1920: Operating instructions Opertating instructions Specifications Service manual Operating instructions

Contents

5DVD-1720/556IMPORTANT SAFETY PRECAUTIONSProduct Safety NoticeSome electrical and mechanical parts have specialsafety-related characteristics which are often notevident from visual inspection, nor can the protectionthey give necessarily be obtained by replacing themwith components rated for higher voltage, wattage,etc. Parts that have special safety characteristics areidentified by a ! on schematics and in parts lists. Useof a substitute replacement that does not have thesame safety characteristics as the recommendedreplacement part might create shock, fire, and/or otherhazards. The Product’s Safety is under reviewcontinuously and new instructions are issuedwhenever appropriate. Prior to shipment from thefactory, our products are carefully inspected to confirmwith the recognized product safety and electricalcodes of the countries in which they are to be sold.However, in order to maintain such compliance, it isequally important to implement the followingprecautions when a set is being serviced.Precautions during ServicingA. Parts identified by the ! symbol are critical forsafety. Replace only with part number specified.B. In addition to safety, other parts and assembliesare specified for conformance with regulationsapplying to spurious radiation. These must also bereplaced only with specified replacements.Examples: RF converters, RF cables, noiseblocking capacitors, and noise blocking filters, etc.C. Use specified internal wiring. Note especially:1) Wires covered with PVC tubing2) Double insulated wires3) High voltage leadsD. Use specified insulating materials for hazardouslive parts. Note especially:1) Insulation tape2) PVC tubing3) Spacers4) Insulators for transistorsE. When replacing AC primary side components(transformers, power cord, etc.), wrap ends ofwires securely about the terminals beforesoldering.F. Observe that the wires do not contact heatproducing parts (heat sinks, oxide metal filmresistors, fusible resistors, etc.).G. Check that replaced wires do not contact sharpedges or pointed parts.H. When a power cord has been replaced, check that5 - 6 kg of force in any direction will not loosen it.I. Also check areas surrounding repaired locations.J. Be careful that foreign objects (screws, solderdroplets, etc.) do not remain inside the set.K. Crimp type wire connectorThe power transformer uses crimp typeconnectors which connect the power cord and theprimary side of the transformer. When replacingthe transformer, follow these steps carefully andprecisely to prevent shock hazards.Replacement procedure1) Remove the old connector by cutting the wiresat a point close to the connector.Important: Do not re-use a connector. (Discardit.)2) Strip about 15 mm of the insulation from theends of the wires. If the wires are stranded,twist the strands to avoid frayed conductors.3) Align the lengths of the wires to be connected.Insert the wires fully into the connector.4) Use a crimping tool to crimp the metal sleeve atits center. Be sure to crimp fully to the completeclosure of the tool.L. When connecting or disconnecting the internalconnectors, first, disconnect the AC plug from theAC outlet.