Processor Reset; Troubleshooting Guide - Harman Kardon AVR1550 Service Manual

Troubleshooting Guide

SYMPTOM
Unit does not function when
Main Power Switch 1 is pushed
Display lights, but no sound
or picture
Sound is heard, but Front-Panel
Display does not light
No sound from any speaker;
light around Power switch 2 is red
No sound from surround or
center speakers
Unit does not respond to
remote commands
Intermittent buzzing in tuner
Letters flash in the Channel Indicator
Display P and Digital Audio stops

Processor Reset

In the rare case where the unit's operation or the
displays 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 three min-
utes. 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.
CAUSE
• No AC Power
• Intermittent input connections
• Mute is on
• Volume control is down
• Display brightness is turned off
• Amplifier is in protection mode
due to possible short
• Amplifier is in protection mode
due to internal problems
• Incorrect surround mode
• Incorrect configuration
• Stereo or Mono program material
• Speakers not properly connected
• Weak batteries in remote
• Wrong device selected
5
• Remote sensor is obscured
• Local interference
• Digital audio feed paused
To clear the AVR 1550's entire system memory
including tuner presets, output level settings,
delay times and speaker configuration data, first
put the unit in Standby by pressing the System
Power Control button 2. Next, press the
Tone Mode 6 and the RDS @ buttons simul-
taneously.
The unit will turn on automatically and display
the RESET message in the Main
Information Display M. Note that once you
have cleared the memory in this manner, it is nec-
essary to re-establish all system configuration
settings and tuner presets.
SOLUTION
• Make certain AC power cord is plugged
into a live outlet
• Check to see if outlet is switch controlled
• Make certain that all input and speaker
connections are secure
• Press Mute button 2
• Turn up volume control
• Follow the instructions in the Display Brightness section
on page 23 so that the display is set to VFD FULL
• Check speaker-wire connections for shorts at receiver
and speaker ends
• Contact your local Harman Kardon service depot
• Select a mode other than Stereo
• Check speaker mode
• With (analog or digital) Dolby surround modes, the surround
decoder may not create rear-channel
information from non-encoded programs
• Check speaker-wire connections or use test tone
to verify connections (see page 18)
• Change remote batteries
• Press the AVR selector 5
• Make certain front-panel sensor is visible to remote or
connect remote sensor
• Move unit or antenna away from computers, fluorescent lights,
motors or other electrical appliances
• Resume play for DVD
• Check that Digital Signal is fed to the Digital Input selected
NOTE: Resetting the processor will erase any
configuration settings you have made for speak-
ers, output levels, surround modes, 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 depot.
TROUBLESHOOTING GUIDE