Harman Kardon AVR 10 Reference manual

harman/kardon Service Bulletin
Service bulletin # 9706 November 1997 Warranty labor rate: MINOR repair
To: All harman/kardon Service Centers
Models: AVR 10/20/25/3250; AVI 100/150/200
Subject: Remote Control has stopped working
In the event you receive a complaint about a remote control that has stopped working, perform
the following tests:
1) Remove the batteries and confirm they are not weak or defective (battery voltage should be 1.4 volts
or more). Replace batteries if necessary; both batteries in remote control should be replaced.
2) Point the remote towards the corresponding receiver/amplifier and confirm the remote control
functions operate as intended.
3) If Remote Control still doesn’t work:
Remove batteries, and with an alligator clip lead or other jumper wire, short the positive and negative
tabs inside the control together. (See drawing) This short will drain any remaining charge from
the capacitors in the remote control and re-set the microprocessor.
4) Re-insert batteries and test the functions as per item (2) above.
NOTE: This procedure may also work for other h/k model remote controls not listed above.
harman/kardon Incorporated 250 Crossways Park Drive, Woodbury New York 11797 [phone]

harman/kardon Service Bulletin
Service bulletin # 9502 - February 1995 Warranty labor rate: MAJOR repair
To: All harman/kardon Service Centers
Models:AVR-20/AVI-150 Surround receiver/amplifier
Subject: Low impedance protect circuit, intermittend shut down.
The power rating for the AVR-20 and AVI-150 is 60 Watts into 8 Ohms. The AVR-20 and AVI-150
protection circuits will not activate until the loudspeaker impedance drops below 4 Ohms. During
transients in certain CD program material, the instantaneous impedance of some loudspeakers with
impedance ratings of “8 Ohms” can drop well below 4 Ohms. As result, the low impedance protection
circuit will be activated.
In the event you receive from a consumer one of these products with the complaint “unit shuts down
intermittendly” change the components indicated in the table below. After the change, confirm the idling
current by measuring the voltage between the emitters of the output transistors. The test points are
TP1/TP2 and TP3/TP4. The voltage reading should stabilize at 26 mV after the unit has been switched on
for at least 15 minutes.
If needed, adjust idling current potentiometers VR251L/VR251R until you read 26 mV.
Change From To Part #
Driver Transistor Q214L/214R 2SC2690(A) 2SC4883(A) 2028307101
Driver Transistor Q215L/Q215R 2SA1220(A) 2SA1859(A) 2028007101
Power Transistor Q216L/Q216R 2SC3181 (O) 2SC3182(O) 2028307101
Power Transistor Q217L/Q217R 2SA1264(O) 2SA1265(O) 2028007101
Resistor R244L/244R 1.8kOhm 1.8kOhm 1/8 W GD05182160
Resistor R243L/R243R 2.2 kOhm 2.0 kOhm 1/8 W 1-118-202-25
Capacitor * C223L/C223R 0.068mfd 10.0 mfd 16 V E510601610
*Minus to emitter of Q218L / Q218R

harman/kardon Service Bulletin
Service bulletin # 9601 -January 1996 Warranty labor rate: MINOR repair
To: All harman/kardon Service Centers
Models:AVR-20/AVR-20II Surround receiver/amplifier
AVR-25/AVR-25II
Subject: Poor or intermittent reception of FM
_____________________________________________________________________________________
In the event you receive a unit from a consumer with a complaint “FM cuts out intermittently” use the
procedure listed below in addition to the procedure listed in the service manual for FM alignment.
To supplement the manual, for FM center tuning alignment follow these procedures;
AVR20/AVR20II
Alignment Equipment
settings Adjust Adjust For
Quadrature Tune to a known strong FM
station around center of the
band (98.1MHz)
T803 0 VDC across R809, confirm by tuning to
another strong station.
Repeat step 1 in service manual for minimum distortion. Repeat both steps again for optimum sensitivity.
*note: step #4 in AM IF states adjustment point VR802, should be VR801
step #2 in FM IF states adjustment point VR801, should be VR802
AVR25/AVR25II
Alignment Equipment
settings Adjust Adjust For
Quadrature Tune to a known strong FM
station around center of the
band (98.1MHz)
T903 0 VDC across R914, confirm by tuning to
another strong station.
Repeat step 1 in service manual for minimum distortion. Repeat both steps again for optimum sensitivity.
harman/kardon Incorporated, 80 Crossways Park West, Woodbury, New York 11797 [phone]