Panasonic EB-GD75 Service Manual

Also see for EB-GD75: Operating instructions

Contents

TEST AND MEASUREMENTMCUK011201C8 Section 6 Issue BService Manual – 29 – Revision 06 TEST AND MEASUREMENT6.1. IntroductionThis section provides information on testing the telephone. The layout is as follows:Calibration procedures are described in Section 7.6.2. Any-Layer Interstitial Via Hole (ALIVH) PCBs6.2.1 General InformationTo reduce overall size and provide enhanced speech and data performance, an Any-Layer Interstitial Via Hole (ALIVH) PCBis used in this telephone. ALIVH PCBs are multi-layer boards which have an IVH structure in all inter-layers and can providean inter-layer connection immediately under the land of a component. In addition, the PCB has no through holes and anynumber of layers can be interconnected.As the specification and performance characteristics of ALIVH PCBs differ from that of conventional multi-layered boards,special attention is required when handling and repairing these assemblies.Moisture AbsorbencyThe ALIVH PCB is more absorbent than a conventional PCB because of the nature of its material. Its aramid substrate ishydrophilic, i.e. it absorbs moisture from the air. If, after having absorbed moisture, the ALIVH PCB is submitted to re-flow orrepair process, moisture in the board can suddenly evaporate and cause vapour explosion.Copper Foil Peel Strength (Land Detachment Resistance)The ALIVH PCB is slightly less resistant to copper detachment force than conventional boards. Therefore, it is necessary toensure that solder is melted sufficiently before a component is removed from the board.Warping PropertyThe ALIVH PCB has a smaller Young's Modulus and is therefore more pliant than conventional boards. It is important that theALVIH PCB is not bent when component placement is performed.6.2.2 Repair ProceduresTo prevent problems caused by moisture absorption, it will be necessary to perform dehydration of ALIVH PCBs in a suitableoven or similar heating device prior to repair. The boards should be heated at 85 °C for a duration of at least ten hours.The repair should also be performed under the following conditions:Soldering IronThe temperature of the tip of the soldering iron should be 350 °C ±10 °C for an application time of five seconds or less.Removal and re-mounting of components should be performed only once at any component position.Section 6.2: Handling and repair of Any-Layer Interstitial Via Hole (ALIVH) PCBs.Section 6.3 External testing: describes equipment requirements and general set up procedure.Section 6.4 Complete Unit Test Setup: describes how the items of test equipment are used together and general setup procedure.Section 6.5 Channel box test commands: provides detailed explanation of the different commands available usingthe test equipment and channel-box software.CAUTIONThe telephone handset uses an ALIVH PCB assembly, the substrate of which is hydrophilic. To avoid damaging the ALIVH PCB, thespecialist equipment and procedures described below must be employed when replacing suspect or faulty components.Note: To avoid land detachment, do NOT apply excessive force on the soldering iron when heating the board. Ensurethat the solder has melted sufficiently to allow component removal without damaging the board.