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Harman Kardon Service Bulletins
Service Bulletin # 9706
Date: November 1997
To: All harman/kardon Service Centers
Models: AVR 10/20/25/3250; AVI 100/150/200
Subject: Remote Control has stopped working
Warranty labor rate: MINOR repair
In the event of a complaint about a remote control that has stopped working, perform the following tests:
Remove 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 the remote control should be replaced.
Point the remote towards the corresponding receiver/amplifier and confirm the remote control functions operate as intended.
If the 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. This action will drain any remaining charge from the capacitors in the remote control and re-set the microprocessor.
Re-insert batteries and test the functions as per item (2) above.
Diagram Description: A drawing shows a remote control with an arrow pointing to the battery compartment. A second diagram illustrates two battery terminals labeled '+' and '-' with the instruction 'SHORT THESE TWO CONTACTS TOGETHER'.
Note: This procedure may also work for other h/k model remote controls not listed above.
Company: harman/kardon Incorporated, 250 Crossways Park Drive, Woodbury New York 11797 (516) 496-3400
The power rating for the AVR-20 and AVI-150 is 60 Watts into 8 Ohms. The 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, causing the low impedance protection circuit to activate.
In the event a consumer reports the complaint "unit shuts down intermittently", 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.
In the event a unit is received 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.
Correction 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.
Company: harman/kardon Incorporated, 80 Crossways Park West, Woodbury, New York 11797 (516) 496 3400
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