Harman Kardon AVR35, Service Manual

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harman/kardon
Service Bulletin
Service bulletin # HK2000-01 Rev1 April 2001 Warranty labor rate: MINOR repair
To: All harman/kardon Service Centers
Models: AVR35/AVR45/AVR65
Subject: No Output in Surround Modes
In early versions of the AVR35, AVR45 and AVR65, the IC484 +5v regulator may overheat and go into thermal
protection. Its +5 volt output will cease; when this happens the AC-3 and Surround Processor cannot function
normally, and the audio output may go dead, or experience a long delay before any surround mode comes on.
In the event you receive an AVR35, AVR45 or AVR65 A/V receiver with the complaint “when attempting to
use the surround modes, the unit’s output goes dead after several minutes, or may not change from
stereo into the surround modes until after a long delay, or not change at all” (the words ‘No Data’ may
also appear in the display), perform the following modification:
1) Remove the top cover, (14) Philips screws; set the unit on its side and remove the bottom cover, (8) Philips
screws.
2) Locate R486, R495 (10 ohm 1 watt resistors) and IC484 (+5v regulator) on the MAIN PCB. See Figure 1.
The parts are located near the front right corner of the MAIN PCB when viewed from the front. IC484 is
attached to a rectangular aluminum heatsink.
3) Desolder and remove R486, R495 and IC484. The IC484’s heatsink has two additional soldered
connections at the bottom of the MAIN PCB. See Figure 2.
4)
Replace R486 and R495 with (2) 15 ohm 3 watt resistors, (h/k part# J1771150771X), soldered in series to
measure 30 ohms each. See Figure 3. Replace IC484 with +5v regulator, J1217780002X).
5) Replace heatsink with new larger part, (h/k part# J5241003040XX)
6) Use silicon grease when attaching the new regulator to the heatsink, and tighten it sufficiently with its single
mounting screw before re-soldering in place.
7) When all new parts are installed, replace both the top & bottom cover.
8) Test the unit by connecting a music source to a digital input, either optical or coaxial, powering it up and
monitor the receiver playing normally for extended period of time.
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AVR35 harman/kardon