Pioneer DVH-3900MP/XZ/EW5 Service Manual Download Page 6

Page: 6 / 110

DVH-3900MP/XZ/EW5

1. SERVICE PRECAUTIONS

1.1 SERVICE PRECAUTIONS

1. Always disconnect the power source before:

1) Removing or reinstalling any component, circuit board, module or any other instrument assembly.
2) Disconnecting or reconnecting any instrument electrical plug or other electrical connection.
3) Connecting a test substitute in parallel with an electrolytic capacitor in the instrument.

CAUTION

: A wrong part substitution or incorrect polarity installation of electrolytic capacitors may result in an

explosion hazard.

2. Do not defeat any plug/socket B+ voltage interlocks with which instruments covered by this service

manual might be equipped.

3. Do not apply power to this instrument and or any of its electrical assemblies unless all solid-state

device heat sinks are correctly installed.

4. Always connect a test instrument’s ground lead to the instrument chassis ground before connecting

the test instrument positive lead. Always remove the test instrument ground lead last.

1) The service precautions are indicated or printed on the cabinet, chassis or components. When servicing,

follow the printed or indicated service precautions and service materials.

2) The Components used in the unit have a specified conflammability and dielectric strength. When replacing

any components, use components which have the same ratings. Components marked in the circuit diagram
are important for safety or for the characteristics of the unit. Always replace with the exact components.

3) An insulation tube or tape is sometimes used and some components are raised above the printed writing

board for safety. The internal wiring is sometimes clamped to prevent contact with heating components.
Install them as they were.

4) After servicing always check that the removed screws, components and wiring have been installed correctly

5. IC1503 (EEPROM) on Option Code Ass'y can not be supplied as a service part, because it needs unique

data writing.
If IC1503 is defective, replace whole of Option Code Ass'y.

6. This model can playback only 12cm discs.

and that the portion around the service part has not been damaged. Further check the insulation between
the blades of attachment plug and accessible conductive parts.

Service Precaution

NOTES ON SOLDERING

   For environmental protection, lead-free solder is used on the printed circuit boards mounted in this unit.
  Be sure to use lead-free solder and a soldering iron that can meet specifications for use with lead-free solders for repairs
  accompanied by reworking of soldering.

   Compared with conventional eutectic solders, lead-free solders have higher melting points, by approximately 40 C.
  Therefore, for lead-free soldering, the tip temperature of a soldering iron must be set to around 373 C in general, although
  the temperature depends on the heat capacity of the PC board on which reworking is required and the weight of the tip of
  the soldering iron.

Compared with eutectic solders, lead-free solders have higher bond strengths but slower wetting times and higher melting
temperatures (hard to melt/easy to harden).

The following lead-free solders are available as service parts:
Parts numbers of lead-free solder:
  GYP1006 1.0 in dia.
  GYP1007 0.6 in dia.
  GYP1008 0.3 in dia.

www. xiaoyu163. com

QQ 376315150

TEL 13942296513