Read Harman Kardon AVR 500 (serv.man10) Technical Bulletin online
harman/kardon Incorporated 250 Crossways Park Drive, Woodbury New York 11797 (516) 496-3400
1
harman/kardon
Service Bulletin
Service bulletin # H/K2000-02 March 2000
Warranty labor rate: MAJOR repair
To:
All harman/kardon Service Centers
Models: AVR300, AVR500
Subject: Random Noise, Erratic Output in DTS Mode
In the event you receive an AVR300 or AVR500 receiver with the complaint “there is distortion, random
noise or gaps in the program material when in the DTS mode”, perform the following procedure:
noise or gaps in the program material when in the DTS mode”, perform the following procedure:
REMOVAL AND MODIFICATION OF THE DSP BOARD
1) Remove the top cover, (14) Black Phillips screws.
2) Locate the DSP PC Board; Figure 1. Remove the two metal braces at the top of the unit. If necessary, cut
2) Locate the DSP PC Board; Figure 1. Remove the two metal braces at the top of the unit. If necessary, cut
the cable ties attached to the braces to move any wires away from the area.
3) Pull the white 22 conductor ribbon cable at the rear of the DSP PC Board straight out of its receptacle.
4) Unplug the white 5 conductor molex cable at the top of the DSP PC Board.
5) Remove the (33) plated Phillips screws on the left side of the rear backplate; see Figure 2. Do not remove
4) Unplug the white 5 conductor molex cable at the top of the DSP PC Board.
5) Remove the (33) plated Phillips screws on the left side of the rear backplate; see Figure 2. Do not remove
any additional screws on the right side. If using a power tool, use care and minimum effort to avoid
damaging the various plastic receptacles.
damaging the various plastic receptacles.
6) Remove all three black plastic plugs that cover the optical inputs at the rear of the DSP PC Board.
7) Pull on the left side of the rear backplate, away from the receiver chassis; you should be able to pull it away
7) Pull on the left side of the rear backplate, away from the receiver chassis; you should be able to pull it away
enough to allow the DSP PC Board to be pulled straight up and out of the receiver.
8) Proceed with the modifications on page 2.
Model
Serial Number
120V
Serial Number
230V RDS
STATUS
ACTION
AVR300
AVR500
TH0001-01000
To
TH0001-13886
TH0002-01000
To
TH0002-10460
TH0005-01000
To
TH0005-03317
TH0006-01000
To
TH0006-02795
Random Noise, Erratic
Output or Gaps in Program
Material when in DTS Mode
Modifications to DSP Board:
Add ground wire;
Change R756 & R755
from 600
Ω
to 33
Ω
AVR300
AVR500
TH0001-13887
Or higher
TH0002-10461
Or higher
TH0005-03318
Or higher
TH0006-02796
Or higher
Modified by factory
NONE REQUIRED
harman/kardon Incorporated 250 Crossways Park Drive, Woodbury New York 11797 (516) 496-3400
2
Models: AVR300, AVR500 Subject: Random Noise, Erratic Output in DTS Mode
9) Ground Reinforcement:
Using an insulated 16AWG wire, Connect Negative sides of the following capacitors on the bottom side of the
PCB as shown below. Negative side of each cap will have a white mark on the component side of the PCB.
PCB as shown below. Negative side of each cap will have a white mark on the component side of the PCB.
A. Negative polarity of C746 Elec Cap (1uF/50V) in the proximity of ROM IC709
B. Negative polarity of C749 Elec Cap (1uF/50V) in the proximity of IC708 DSP IC
C. Negative polarity of C744 Elec Cap (1uF/50V) in the proximity of IC710 74VHC574
B. Negative polarity of C749 Elec Cap (1uF/50V) in the proximity of IC708 DSP IC
C. Negative polarity of C744 Elec Cap (1uF/50V) in the proximity of IC710 74VHC574
C
B
A
10) Replace:
Change both R756 & R755 from 600
Ω
to 33
Ω
1/10W SMD resistors (h/k part#
292-33.2)
. See
location below.
11) Replace DSP PC Board back into its (3) receptacle plugs atop the MAIN PCB.
12) Replace all screws, braces, and any cable ties that were cut during disassembly. Before tightening the
12) Replace all screws, braces, and any cable ties that were cut during disassembly. Before tightening the
screws, make sure all PCB’s and their RCA jacks are firmly seated in their respective holes in the rear
backplate. If using a power tool, use care and minimum effort to avoid damaging the various plastic
receptacles.
backplate. If using a power tool, use care and minimum effort to avoid damaging the various plastic
receptacles.
13) Plug both the 22 conductor ribbon cable and the 5 conductor molex cable back into their receptacles.
14) Replace the top cover and optical plugs.
15) Test unit by powering up the receiver and playing a source with DTS encoded material; confirm the
14) Replace the top cover and optical plugs.
15) Test unit by powering up the receiver and playing a source with DTS encoded material; confirm the
complaint of Random Noise or Erratic Output is no longer occurring.
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