HK 3770 (serv.man8) - Harman Kardon Audio Service Manual (repair manual). Page 8

HK 3700/3770

troubleshooting

14

unit does not function when main power button is turned On

•  Make sure ac power cord is plugged into a live outlet
•  check to see whether outlet is switch-controlled

no sound from the receiver

•  Make certain that all input and speaker connections are secure.
•  press Mute button
•  turn up Volume control
•  press correct Source Selector
•  press Speaker 1 or Speaker 2 button
•  unplug headphones
•  Replace jumper pins or, if external amplifier is in use, make sure it is turned 

On

no sound from any speaker

•  check speaker-wire connections for shorts at receiver and speaker ends
•  contact your local Harman Kardon service center

unit does not respond to remote commands

•  change remote batteries 
•  Make certain front-panel sensor is visible to remote or connect an optional 

remote sensor

Intermittent buzzing in tuner

•  Move unit or antenna away from computers, fluorescent lights, motors or 

other electrical appliances

no video image

•  connect the source’s composite video output to the correct video input on 

the HK 3700/3770

•  press the correct Source Selector on the HK 3700/3770
•  connect the HK 3700/3770’s Video Monitor Output to a composite video 

input on your television or video display

•  consult the manual for your television for instructions on selecting the 

correct video input

•  It is not possible to view video while listening to the phono, tape/cdR or cd 

sources or to the tuner

audio sources sound distorted

•  Only plug a device into the phono Inputs if it is a turntable with a moving-

magnet cartridge, or if it is a turntable with a moving-coil cartridge with a 
phono preamp

•  do not use a turntable with any inputs other than the phono Inputs, unless 

it has a moving-magnet-type cartridge and includes a phono preamp

If  your  HK  3700/3770  receiver  does  not  perform  the  way  you  think  it  should,  check  whether  the  problem  is  covered  in  this  section  before  contacting  your  dealer  or  a                                                       
Harman/Kardon representative.

Harman Kardon

HK 3770 Service Manual

Page 8 of 120