Pioneer XR-P340M XR-P74OM. XR-P64OM, XR.P34OM xR.-P7 4o-, XR-P64HJ,XR-P340, HandlingPrecautions

XR-P74OM. XR-P64OM, XR.P34OM xR.-P7 4o-, XR-P64HJ_,XR-P340

FM/AM TUNERMODULE

Fig. 1 -3AdjustmentPoints

2 . POWERAMP MODULESECTTON(Referto Fig .2 - 1 . 1

1. HandlingPrecautions

oSince the heat sink and transistor metallic parts are con- nected to the Front Amp output, make sure they do not contact the GND (chassis)or other circuits.

oSince there is residual high voltage in the Power Amp Module Assy +31 (FRONT ASSY FOR 100W) and +B2 (REAR, PWR, PRTEC ASSY) even when the

power is OFF, caution shouldbe exercised.(If necessary, the voltage should be discharged).

aWhen handling the Power Amp Module Assy, make sure you do not touch the fan motor blade.

2. Adjustment and Confirmationof ldle Current

oBasically, the idle crurent needs to be confirmed when replacing a power transistor, driver transistor, or bias transistor, or when the entire split board Assy of the Power Amp Module Assy has been replaced.

oMake sure the heat sink has cooled sufficiently before measuring the idle current. (Temperature should be the

same as room temperature; 25oC is ideal, if possible.) o Idle current stipulated value: 3-50mA.

I Front Amp Side (FRONTASSY FOR 1OOW)

itep Measurement					Item
I	Short both sides of C7L23 afi				C7L24 on the Rear Amp side.
2	Insert a resistor (0.220, 3W or more) in series in the connector
	CN7502 *81	(or -81)	line	(terminal		(Refer	to FiS.2-2.\
					No. 5 or 6).

Lch side

Remarks

Do not operate the Rear Amp side.

For measuring voltage at both sidesof resistor

3		Short both sides of C7524.
		Turn the power ON, wait 6 seconds,and then measurethe resistance
		voltage in Step 2.
5		o	Sameas Steps 1 and 2 above.
		.	Short both sidesotC7523.
	Rch side
		Turn the power ON under the above conditions, and after 6 seconds
6
		measurethe resistancevoltage in Step 2.
		If the measuredidle current is greater than 50mA, perform the follow-
		ing procedure.
8	Lch side	Short between the Point A pattern in Fig. 2-3		using solder.
I	Rch side	Short between the Point B pattern in Fig. 2-3		using solder.
10		After performing Steps 8 and 9, remeasurethe idle current and con-
		firm that it is below 50mA.

Do not operate Rch side.

Lch Idle current l:V/0.22 (0)

Do not operate Lch side.

Connect R7517 to R7515 in a parallel cir- cuit.

Connect R7518 to R7516 in a oarallel cir- cuit.

NOTE:

If the idle current is below 3mA, support a resistor(33kQ)betweenthe emitter and the Q7501(Lch) and Q7502(Rch)biastran- sistor base,and confirm that the idle cunent is within 3-50mA.

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