Bose built invisible amplifier service manual troubleshooting tibose ps

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Framingham, MA 01701-9168 SIZE A FSCM 32108 CLASS FM DWG NO. 172780-TT SHEET 2 of 2 REV. 01 Troubleshooting Tips Bose ® BUILT-INvisible ® Amplifier Refer to the Bose® BUILT-INvisible® Amplifier service manual, reference number 172780 for schematics, PCB layouts and parts lists located on service web site. Preventative Repair Measures Note: Perform the following on all units returned for repair. Product Check Action Built Invisible Amplifier Replace all 100uF, 50V caps as a precaution. The caps may have leaked, causing damage to the surrounding pcb etches and components. Replace the following 100uF, 50V caps with new components, part number 149948-101H. PCB Number Ref Des 175466, 170015 C819, C822 174562 C26, C165, C166 170010 C16, C17, 170021 C107, C207, C307, C407 * Heat sink If a unit returned for service has a gold colored heat sink, Polyimide tape should be added to the heat sink to prevent the personality PCB from shorting to the heat sink. This should be done even if the unit does not exhibit the symptoms mentioned above. Refer to service bulletin 172780-B1. Troubleshooting Tips Product Symptom Check Action Built Invisible Amplifier Dead F800, F801 and F802 Check for open fuses on the power supply board. If one or more are open check for shorted transistors on the amplifier pcb (See tip below). * Dead, blows fuse when powered on Power amplifier PCB Check the transistors that mount to the heatsink assembly for shorts. Also check for cold solder joints on the driver transistors.