JVC KV-V8 service manual How to set the Service position, Mechanism service mode

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.

Main board assembly

TP4001

CTL.P

TP111

D.FF

SW board assembly

TP2253

A FM

TP106

PB FM

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)

CN3006	CP5001	CP5002
Front board
assembly
CN7001
TP7001	TP7002
MECHA TEST	GND

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.

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