DOWNLOAD Harman Kardon HK 3700 Service Manual ↓ Size: 13.75 MB | Pages: 109 in PDF or view online for FREE

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 3700 Service Manual

Page 13 of 109

AMPLIFIER SECTION BIAS ADJUSTMENT

Measurement condition
.No input signal or volume position is minium.
.Do not adjust at FM/AM.

Standard value 
.Ideal current = 48mA (±7%)
.Ideal DC Voltage = 22.5mA (±7%)

CN51

CN41

DC VOLTMETER : Connect to
CN51 ( L-CH), CN41 ( R-CH)

No.

Channel

Adjust for 

Adjust

1

Left

22.5mV(±7%)

CN51

2

Right

22.5mV(±7%)

CN41

Harman Kardon

HK 3700 Service Manual

Page 14 of 109

1. Standby mode.
2. Press the Tun mode key for a few seconds.

3. VFD will show as below.

4. Complete reset.

Harman Kardon

HK 3700 Service Manual

Page 15 of 109

1.

Copy the latest firmware files(*.fw and *.ve) to a USB stick's root directory.

2.

Plug a USB stick into the front panel.

3.

Power ON by using the remote control or the set button.

4.

After 30 seconds, press 'STEREO' key and 1,7,1,8 + 'ok' buttons on R/C.

Followings will be shown on the VFD.

VFD 1st line : SYSTEM UPGRADE
VFD 2nd line : Searching..

5.

After USB searching, Venice upgrade begins.
Followings will be shown on the VFD.

VFD 1st line : VENICE UPDATE
VFD 2nd line : [Updating %]
It takes about 6~8 minutes to upgrade the firmware.

Harman Kardon

HK 3700 Service Manual

Page 16 of 109