Service Position; Mechanism Service Mode - JVC KV-V8 Service Manual

1.4 Service position

This unit has been designed so that the Mechanism and Main
board assemblies can be removed together from the chas-
sis assembly. Before diagnosing or servicing the circuit
boards, take out the major parts from the chassis assembly.
1.4.1 How to set the "Service position"
(1) Refer to the disassembly procedure and perform disas-
sembly of the major parts before removing the Cassette
housing assembly.
(2) Remove the combined Cassette housing, Mechanism
and Main board assemblies.
(3) Connect the wires and connectors of the major parts that
have been removed in step (1). (Refer to Fig. 1-4-1a.)
(4) Place the combined Mechanism and Main board assem-
blies upside down.
(5) Insert the power cord plug into the power outlet and then
proceed with the diagnostics and servicing of the board
assembly.
Notes:
• Before inserting the power cord plug into the power
outlet, make sure that none of the electrical parts are
able to short-circuit between the workbench and the
board assembly
• For the disassembly procadure of the major parts and
details of the precautions to be taken, see "1.3 Disas-
sembly/assembly method".
• If there are wire connections from the Main board and
Mechanism assemblies to the other major parts, be
sure to remove them first before performing step (2).
• When carrying out diagnosis and repair of the Main
board assembly in the "Service position", be sure to
ground both the Main board and Mechanism assem-
blies. If they are improperly grounded, there may be
noise on the playback picture or FDP counter display
may move even when the mechanism is kept in an in-
operative status.
• In order diagnose the playback or recording of the cas-
sette tape, set the Mechanism assembly to the required
mode before placing it upside down. If the mechanism
mode is changed (including ejection) while it is in an
upside down position the tape inside may be damaged.
• When checking the operation or performing adjust-
ments to the VCP main unit, it is necessary to connect
the power cable (Car Cable) to the VCP main unit so
that DC power is supplied. Also, when using the re-
mote control unit, it is required to connect the IR re-
ceiver. (by using either the provided or optional acces-
sories)
1-4
Main board assembly
TP4001
CTL.P
TP111
D.FF
SW board
assembly
CN3006
Front board
assembly
CN7001
TP7001
MECHA TEST
Fig. 1-4-1a

1.5 Mechanism service mode

This model has a unique function to enter the mechanism
into every operation mode without loading of any cassette
tape. This function is called the "Mechanism service mode".
1.5.1 How to set the "Mechanism service mode"
(1) Unplug the power cord plug from the power outlet.
(2) Remove the Front panel assembly and Cassette hous-
ing assembly. (Take care not to pull the flat wire.)
(3) Connect TPGND and TP7001(TEST) on the Front board
assembly with a jump wire.
(4) Insert the power cord plug into the power outlet.
(5) Turn on the power. When the loading has completed,
the mechanism enters the desired mode.
TP2253
A FM
TP106
PB FM
CP5001 CP5002
TP7002
GND