Bose FREESPACE 4400, Service Manual

Page: 63 / 107

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TEST PROCEDURE SETUP
Equipment Requirements
• 400 MHz Pentium-based PC with a minimum of 256 MB of RAM and 50 MB of of
available hard drive space
•
4x CD-ROM drive
• One of the following operating systems: Microsoft ® Windows ® NT, 2000 or Vista
• 800 x 600 display
•
The Bose
®
FreeSpace
®
4400 Installer™ software version 1.0 or higher
• An RS-232 serial cable, M/F with DB9 connectors
•
An oscilloscope
• An audio signal generator similar to an Audio Precision ATS-1
• A digital multimeter
•
Four 100 Ohm, 250 Watt load resistors
• One 2 Ohm, 250 Watt load resistor
Test Strategy and Conditions
Verify the customer complaint. Read any applicable notes that came in with the unit. Then
power up the unit and attempt communication using the Bose Installer program. If successful,
examine the error log files to try to determine the nature of the failure.
The amplifier will be put into a known state for test by first updating the unit’s microcode using
the Bose Installer program. This resets the unit, sets the EQ’s and gains to the proper levels
and maps the Zone 1 input to Zones 1 – 4 at the outputs.
Note: Loading new host microcode will place the unit into the factory default condition and will
also erase the stored unit serial number.
Once the update is completed, the unit will need to be configured so that Zone 1 input is
mapped to the Zone 1 amplifier output, Zone 2 to Zone 2, etc. Once this is completed the
amplifier will be properly configured for test.
All AC audio measurements must be band limited to 30 kHz. AC power must be applied to the
4400 amplifier product variants as follows:
All audio inputs must be terminated with 600 Ohms. All line level outputs must be terminated
with 400 Ohms. All amplifier outputs must be terminated with 50 Ohms.
Product Code Country VAC
040753 US/Canada 120 VAC/60 Hz
040754 Europe 230 VAC/50 Hz
040742 Japan 100 VAC/60 Hz
040755 UK/Singapore 230 VAC/50 Hz
040756 Australia 240 VAC/50 Hz