Harman Kardon AVR 660 Service Manual / Technical Bulletin ▷ View online
harman/kardon
Service Bulletin
AVR 660 AVR 760 AVR 7550HD
November 2009
Harman International
8500 Balboa Blvd., Northridge, CA 91329, USA
Service bulletin # HK2009-002
To:
All harman/kardon Service Centers
Models:
AVR 660/230, AVR 760/230 and AVR7550HD
Subject: Fan
Noise
In the event you receive one of the above-mentioned AVR models with the complaint “FAN NOISE”, carry
out the following modification.
out the following modification.
Parts: Kit # AVR760660FANKIT (220 Ohms / 1W resistor in parallel with 330uF 25V 105C Electrolytic Cap
To Black wire of Fan supply
Soft wire must go to D-Ground on connector Board
1. Remove the top cover (13 screws)
2. Locate the FAN (picture 1)
2. Locate the FAN (picture 1)
Picture 1
BLACK and RED Wire for FAN supply
FAN
Picture 2
3. Locate the Black wire (See Picture 1 close up)
4. Cut the Black wire as shown in picture 2
harman/kardon
Service Bulletin
AVR 660 AVR 760 AVR 7550HD
November 2009
Harman International
8500 Balboa Blvd., Northridge, CA 91329, USA
Picture 3
5. Connect the Kit with the two ends of the Black wire
that was cut in item 4 by twisting the pin of the kit
around the two ends and solder it. (See Picture 3) add
flex to cover the solder point.
Picture
4
6. Solder the other end of the kit to solder joint indicated in
Picture 4. This is on the connector board.
7. Fix the kit to the cables as shown on picture 5
8. Re-mount the top-cover
Picture 5
9. Confirm the unit is working
Note: This modification changes the behavior of the Fan control.
Before modification: Fan will start after 10-20 minutes when a certain
temperature is reached inside the unit. The Fan starts a level 1 and from there on
steps up in levels as heat sink temperature goes up, following an increase in the
sound level.
After modification: A new level 0 is added, This starts the Fan as soon the unit is
ON, but the Fan will run at slow speed that does not create Fan noise, and is
slower than level 1. This results in sufficient cooling when playing at low sound
levels, and the user will not hear the Fan when listing to TV or other sources at low
sound level (volume up to about -40dB, depending on the source) and will go to
level 1 or higher levels, if the sound level is increased.
Model
Serial number
Status
Action
AVR 660/230
AVR 760/230
AVR 7550HD
AVR 760/230
AVR 7550HD
TBA
If the customer complaint of
Fan noise then perform
above modification
Fan noise then perform
above modification
Modification
Display