Bose freespace 4400 amplifier 294963 troubleshooting rev00 fs4400 amp

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Framingham, MA 01701-9168 SIZE A FSCM 32108 CLASS FM DWG NO. 294963-TT SHEET 2 of 5 REV. 00 Troubleshooting Tips FreeSpace ® 4400 Amplifier Refer to the FreeSpace 4400 amplifier service manual, reference number 294963-SM for schematics, PCB layouts and parts lists. Its located on the Service web site at http://intranet.bose.com/tsg or http://serviceops.bose.com on the Pro Products page. Preventative Repair Measures Note: Perform the following on all units returned for repair. Product Check Action FreeSpace 4400 amplifier There are no preventative measures to perform on this amplifier. Troubleshooting Tips Product Symptom Check Action FreeSpace 4400 amplifier Outputs 1 and 2 and/or 3 and 4 fault LEDs lit. System STATUS LED is lit red Ribbon cables Output FETs Amplifier setup and installation wiring Error log for amplifier module fault conditions Power supply fuses 1. Verify that all of the ribbon cables that connect to the DSP and the other boards are properly seated into their connectors. Replace any damaged cables. 2. Check the outputs FETs on the upper and lower amplifier boards. Verify that they are properly secured to the heatsink and that they are not shorted to it. 3. Check for a shorted speaker line in the installation wiring. 4. Check that the source is not overdriving the channel. 5. Check for loudspeaker transformer saturation. Verify that the proper loudspeaker EQs are being used. 6. Line voltage too high (surge). Check the units error log for an entry that the rail voltage exceeded 150V in 70V mode (US installs) or 190V in 100V mode (Euro). 7. Live voltage too low (brownout) Using the FreeSpace Installer software, check the units error log for an entry that the rail voltage was lower than normal by at least 20%. 8. 70/100V mode switch position changed with unit operating. Check that the output voltage setting (70 or 100V) is correct for the region the unit is used in. Check that the AC input voltage selection switches are set properly for the region. 9. Blown power supply fuse (not the AC line fuse). Check the outputs FETs on the upper and lower amplifier boards. Verify that they are properly secured to the heatsink and that they are not shorted to it. Replace the fuse and perform the test procedures in the service manual. If the fuse blows again, replace the amplifier module and retest.

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Framingham, MA 01701-9168 SIZE A FSCM 32108 CLASS FM DWG NO. 294963-TT SHEET 3 of 5 REV. 00 Product Symptom Check Action FreeSpace ® 4400 amplifier System STATUS LED is lit red Error log and system wiring 1. Switch the system to STANDBY and then back to active again. If the SYSTEM STATUS LED is green, the system may have logged an error. Check the error log on the unit using the FS 4400 Installer software. 2. Switch the system to STANDBY. Set the power switch on the rear panel to OFF. Wait for the STANDBY indicator to turn off. Set the power switch to ON. Press the STANDBY switch and check to see if the SYSTEM STATUS LED is now green. 3. Switch the system to STANDBY. Set the power switch on the rear panel to OFF. Disconnect all input and output signal cables. Set the power switch to ON. Press the STANDBY switch. Reconnect one cable at a time and check the SYSTEM STATUS LED and the error log to see if there are errors. FreeSpace 4400 amplifier System STATUS LED is lit red Error log for power-on self test failure The power-on self test (POST) checks five major hardware components. Connect to the system using the FreeSpace Installer software to view the error log messages. The failures types are below. 1. Host controller -“ will cause the message Power- on self test incomplete to appear in the host controller test section of the error log. This is usually caused by a SRAM address failure. 2. Flash memory -“ Contains the system configuration, design file and the system event schedule. Error log will have an entry Power-on self test incomplete in the host controller flash test section. 3. Peripheral controller -“ This monitors contact closures, rear panel connections and user interface connections. Error log will have an entry Power-on self test incomplete in the peripheral controller flash test section of the error log. Check the user interface wiring for shorts or a failed keypad. 4. DSP -“ The DSP performs all signal processing and routing functions. Error log will have an entry Power-on self test incomplete in the DSP test section of the error log. 5. Upper and lower amplifier -“ Amplifier channels 1 and 2 are located on the upper amplifier board. Channels 3 and 4 are located on the lower amplifier board. The upper and lower amplifier test determines if the amplifiers are working properly. Error log will have an entry Power-on self test incomplete in the upper or lower amplifier test section of the error log.