Bose-1800V-pwr-sb维修电路原理图.pdf

Bose Service Repair Information Service Home Page Owners Guides REPAIR INFORMATION Lifestyle Systems Acoustic Wave Music System Bose Wave Radio 321 Home Entertainment Systems Lifestyle Music Centers Powered Bass Modules Powered Speakers Acoustimass Speakers SoundDock 01 Speakers Environmental Speakers 001 Speakers Point 2 Speakers RoomMate Speaker Car Stereo Headphones Multimedia Miscellaneous Products Built-INvisible Product Pro Products Engineer: Technical Writer: Jim SloweyDate: 5/12/98Service Bulletin: 181812-B1Product: 1800V Professional Stereo Amplifier Subject: Excessive hum Solution: The ground needs to be modified. Perform the following procedures: Amplifier Modulation: 1. Ensure that the power has been disconnected from the amplifier. 2. Remove the amplifiers top cover and input module. Refer to the 1800V service manual for the disassembly procedures. 3. Remove the ground jumper W40 from WL8. WL8 is located on the power supply PCB. Cut the other end of the jumper W40 as close to the I/O PCB as possible. Discard the jumper wire W40. Refer toFigure 1for the location of WL8. 4. Place the new ground jumper wires (part number 187463) fast-on connector onto WL8. 5. Insert the end of the new ground wire with the Molex pin into the Molex connector that feeds the 15V to the input module. Use the empty connector location that is directly above the white wire feeding into the connector. This is pin 3 on the Molex connector. Refer toFigure 2. Tie wrap the new jumper wire to the wire bundle making sure that the wire is not touching the heat sink. 6. Check both ends of the new ground wire to ensure that they are properly seated. 7. Replace the amplifiers top cover. Input Module Modification: NOTE: The input module modification should be performed on REV A, 1 and 2 input modules. 1. Remove a minimum of 1/8th square inch of solder mask at the location shown in Figure 3. 2. Solder a piece of #20 solid insulated wire to the locations shown in Figure 3. 3. Replace the input module into the amplifier. NOTE: Remove and insert the input module several times to ensure that the Molex pin is properly seated in the Molex connector. 4. Measure the resistance between the ground on the quick connect and the chassis ground. It should measure 0 ohms. If it measures 10 ohms, repeat the amplifier and input module modification procedures. Figure 1 http:/ (1 of 3)6/25/2010 10:53:33 PMRadioFans.CN 收音机爱 好者资料库Bose Service Repair InformationFigure 2 Figure 3 http:/ (2 of 3)6/25/2010 10:53:33 PMRadioFans.CN 收音机爱 好者资料库Bose Service Repair Information http:/ (3 of 3)6/25/2010 10:53:33 PM