harman/kardon

Service bulletin # H/K2000-02 Rev1 January 2001 To: All harman/kardon Service Centers Models: AVR300, AVR500 Subject: Random Noise, Erratic Output in DTS Mode

Service Bulletin

Warranty labor rate: MAJOR repair
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: 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 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 any additional screws on the right side. If using a power tool, use care and minimum effort to avoid 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 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.
Serial Number 120V TH0001-01000 To TH0001-13886 TH0002-01000 To TH0002-10460 TH0001-13887 Or higher TH0002-10461 Or higher
Serial Number 230V RDS TH0005-01000 To TH0005-03317 TH0006-01000 To TH0006-02795 TH0005-03318 Or higher TH0006-02796 Or higher
STATUS Random Noise, Erratic Output or Gaps in Program Material when in DTS Mode
ACTION Modifications to DSP Board: Add ground wire; Change R756 & R755 from 600 resistor or Capacitor to 33 resistor

AVR300

AVR500

AVR300 AVR500

Modified by factory

NONE REQUIRED

harman/kardon Incorporated 250 Crossways Park Drive, Woodbury New York 11797 (516) 496-3400
Models: AVR300, AVR500 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. 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 C B A Subject: Random Noise, Erratic Output in DTS Mode
10) Replace: R756 & R755. Original parts may be 600 resistors, or Capacitors. Change both to 33 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 screws, make sure all PCBs 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. 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 complaint of Random Noise or Erratic Output is no longer occurring. harman/kardon Incorporated 250 Crossways Park Drive, Woodbury New York 11797 (516) 496-3400