Harman Kardon AVR 645 Service Manual Download Page 28

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TROUBLESHOOTING GUIDE

SYMPTOM

CAUSE

SOLUTION

Unit does not function when Main

• No AC Power

• Make certain that AC power cord firmly connected to the

AC Power Cord

Power Switch is pushed

Socket

and is plugged into a live outlet

• Check to see whether outlet is switch-controlled

Display lights, but there is no sound

• Intermittent input connections

• Make certain that all input and speaker connections

or picture

are secure

•

Mute

is on

• Press

Mute Button

• Volume control is down

• Turn up volume control

Unit turns on, but front-panel

• Display brightness is turned off

• Follow the instructions in the Display Brightness section

display does not light up

on page 44 so that the display is set to

VFD FULL

No sound from any speaker;

• Amplifier is in protection mode

• Check speaker wire connections for shorts at receiver and

light around power switch is red

due to possible short

speaker ends

• Amplifier is in protection mode

• Contact your local Harman Kardon service center

due to internal problems

No sound from surround or

• Incorrect surround mode

• Select a mode other than Stereo

center speakers

• Input is monaural

• There is no surround information from mono sources

• Incorrect configuration

• Check speaker mode configuration

• Stereo or Mono program material

• The surround decoder may not create center- or rear-channel

information from nonencoded programs

Unit does not respond to

• Weak batteries in remote

• Change remote batteries

remote commands

• Wrong device selected

• Press the AVR selector

• Remote sensor is obscured

• Make certain front-panel sensor is visible to remote

or connect remote sensor

Intermittent buzzing in tuner

• Local interference

• Move unit or antenna away from computers, fluorescent

lights, motors or other electrical appliances

Letters flash in the channel indicator

• Digital audio feed paused

• Resume play for DVD

display and digital audio stops

• Check that Digital Input is selected

Fan does not appear to operate

• Additional cooling may not be required

• The fan is activated only when additional cooling is required due to

high internal temperature, it is normal for the fan to be inactive at
normal volume levels

In addition to the items shown above, additional information on troubleshooting possible problems with your AVR 645, or installation-related issues, may be found in the list of
“Frequently Asked Questions” which is located in the Product Support section of our Web site at www.harmankardon.com.

Processor Reset

In the rare case where the unit’s operation or the dis-
plays seem abnormal, the cause may involve the erratic
operation of the system’s memory or microprocessor.

To correct this problem, first unplug the unit from the
AC wall outlet and wait at least 3 minutes. After the
pause, reconnect the AC power cord and check the
unit’s operation. If the system still malfunctions, a
system reset may clear the problem.

To clear the AVR 645’s entire system memory includ-
ing tuner presets, output level settings, delay times and
speaker configuration data, first put the unit in the

Standby Mode by pressing the

Standby/On Switch

. Next, press and hold the

Surround Mode Group

Selector

and the

Tuning Mode Selector

buttons for 3 seconds.

The unit will turn on automatically and display the

RESET

message in the

Upper Display Line

NOTE:

Resetting the processor will erase any configu-

ration settings you have made for speakers, output
levels, surround modes, and digital input assignments,
as well as the tuner presets. After a reset, the unit will
be returned to the factory presets, and all settings for
these items must be reentered.

If the system is still operating incorrectly, there may
have been an electronic discharge or severe AC line
interference that has corrupted the memory or
microprocessor.

If these steps do not solve the problem, consult an
authorized Harman Kardon service center.

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