Harman kardon hk 580 i service manual

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Manual No. 18A

The Harman Kardon
Model hk580i

Digital Synthesized Quartz-Locked
Stereo Receiver

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harman/kardon

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PRECAUTIONS

1 .

Always disconnect the chassis from power line when soldering. Turning the power switch OFF is not enough.
Power line leakage passing through the heating element may destroy the transistors.

Never attempt to do any work on the transistor amplifiers without first disconnecting the AC line cord and
waiting until the power supply filter capacitors have discharged.

Replacement for output and driver transistors, if necessary, must be made from the same beta group as the
original type.

If one output transistor burns out (open or short) always remove all the output transistors in that channel and
check the bias adjustment, the control and other parts in the network with an ohmmeter before inserting a new
transistor. All transistors in one channel will be destroyed if the base biasing circuit is open on the emitter end.

When mounting a replacement power transistor, be sure that the bottom of the flange, the mica insulators and
the surface of the heat sink are free of foreign matter, for they may cause transistor failure.

Silicon grease must be applied between the transistor and the mica insulator, and between the mica insulator and
the heat sink for better heat conduction.

Fuses must be replaced with size and type indicated. Use of other types can expose components to destructive
current levels.

ALIGNMENT PROCEDURES

AM ALIGNMENT

Instruments: 1. AM Signal Generator modulated with 400Hz at 30%.
2. Oscilloscope

3. AC V.T.V.M.

4. DC Voltmeter

Notes: 1 . Set function selector switch to AM position.

2. Connect signal source to a loop placed to radiate signals into AM antenna loop stick (L252).

Step Signal Source Connect Output Meter To Statlsgtflzplay Adjust Adjust For
T251 Maximum output on
VTVM and oscilloscope to ' VTVM and at the same
450kHz TP1 and ground 1610kHz 13:? time clean wave form on
oscilloscope
VTVM and oscilloscope to
450kHz TP2 and ground 1610kHz T254 Same as above
7 DC voltmeter to TP3 and
ground 530kHz L251 1.6V on DC voltmeter
- Same as above 1610kHz T6251 22.5V on DC voltmeter
GOOkHz VTVM to Tape 1 Out jack 600kHz L252 {gmum 9 °"
1400kHz Same as above 1400kHz T6252 Same as above
Repeat steps 5 and 6 for optimum sensitivity.
1000kHz Oscilloscope to Tape 1 Out Clean wave form on
40dB/m(100yV/rn) jack ' 1°°°kHZ VR251 oscilloscope