Bose FreeSpace E4 Series II, Руководство по обслуживанию

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Reference Number: 278977-B2
Product: E4 Series II Business Music System
Subject: Amplifier Module Replacement
The Amplifier / Power Supply PCB assembly, part number 278982-001, originally used on the E4 Series II
amplifier is no longer available. This is due to the Tripath amplifier driver module going obsolete.
The amplifier module assembly used in the FreeSpace
®
4400 amplifier can be used as a replacement part.
This requires some minor modifications to the E4 II chassis and a kit of parts that includes adapter brackets,
screws and an EMI gasket. The entire amplifier assembly, including the heatsink, must be replaced.
Required Parts:
FreeSpace 4400 Amplifier Module Assembly, Bose
®
part number 301391
FreeSpace 4400 Amplifier Module adapter kit, Bose part number 311963
Procedure:
Perform the following steps. Refer to the E4 Series II service manual, reference number 278977-SM, for more
information. Note: This procedure cannot be used on any of the E4 Series I amplifier versions. In addition,
it cannot be used on the E4 Series II Japan version, product code 036006.
E4 Series II Power Amplifier Module Removal
•
Remove the E4 II chassis top cover.
• Disconnect the large ribbon cable from the DSP PCB.
• Remove the three screws that secure the amplifier module to
the chassis standoffs.
• Remove the four screws that secure the amplifier module to the
chassis rear panel. Discard.
• Remove the three nuts that secure the amplifier module
heatsink to the chassis. Retain two of these nuts for re-use.
• Slide the E4 II amplifier module forward, and lift up on the front
edge. Lift the heatsink assembly out of the chassis.
• Disconnect the fan harness from the bottom PCB assembly.
• Disconnect the power transformer cable harness from the
lower amp PCB.
Chassis Modification
•
Using a Dremel tool cut-off wheel or similar, remove the metal
chassis stud located near the middle of the chassis section
where the amplifier module is located. Refer to the top photo
at right. Note: Do not remove either of the chassis studs
located along the metal divider between the amplifier module
and the DSP board.
CAUTION: Be sure to use eye protection and to cover any
exposed circuit boards to prevent metal shavings from shorting out components on the boards.
Using compressed air, blow out the chassis to remove any metal shavings that might remain.
Bose Corporation; The Mountain, Framingham, Ma. 01701-9168
For Technical Assistance Call 1-800-233-4408
Service documentation available online at http://serviceops.bose.com
Service Bulletin
Date Issued: 3/08