Bose ps18 28 48 operation
This is the 33 pages manual for bose ps18 28 48 operation.
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Extracted text from bose ps18 28 48 operation (Ocr-read)
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1 PS18/28/35 Troubleshooting Guide PROPRIETARY INFORMATION THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OF BOSE ® CORPORATION WHICH IS BEING FURNISHED ONLY FOR THE PURPOSE OF SERVICING THE IDENTIFIED BOSE PRODUCT BY AN AUTHORIZED SERVICE CENTER OR OWNER OF THE BOSE PRODUCT, AND SHALL NOT BE REPRODUCED OR USED FOR ANY OTHER PURPOSE. Contents Safety Information ............................................................................................................................. 2 Electrostatic Discharge Senstitive (ESDS) Device Handling ........................................................ 2 Specifications .................................................................................................................................... 3 Theory of Operation .................................................................................................................... 4-21 Setting up a computer to issue TAP commands .......................................................................... 22 Placing the Bass Module into TAP Mode ...................................................................................... 23 Figure 1. DIP switch Up/Down orientation ......................................................................................23 Equalizer Programming Method ....................................................................................................23 Scope Photos ............................................................................................................................ 24-25 Integrated Circuit Diagrams ..................................................................................................... 26-30
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2 PS18/28/35 Troubleshooting Guide 1. Parts that have special safety characteristics are identified by the symbol on schematics or by special notes on the parts list. Use only replacement parts that have critical characteristics recommended by the manufacturer. 2. Make leakage current or resistance measurements to determine that exposed parts are accept- ably insulated from the supply circuit before returning the unit to the customer. Use the following checks to perform these measurements: A. Leakage Current Hot Check-With the unit completely reassembled, plug the AC line cord directly into a 120V AC outlet. (Do not use an isolation transformer during this test.) Refer to UL6500 paragraph 9.1.1. Use a leakage current tester or a metering system that complies with American National Standards Institute (ANSI) C101.1 Leakage Current for Appliances and Underwriters Laboratories (UL) 6500, IEC 60065 paragraph 9.1.1. With the unit AC switch first in the ON position and then in OFF position, measure from a known ear th ground (metal waterpipe, conduit, etc.) to all exposed metal parts of the unit (antennas, handle bracket, metal cabinet, screwheads, metallic overlays, control shafts, etc.), especially any exposed metal parts that offer an electrical return path to the chassis. Any current measured must not exceed 0.5 milliamp. Reverse the unit power cord plug in the outlet and repeat test. ANY MEASUREMENTS NOT WITHIN THE LIMITS SPECIFIED HEREIN INDICATE A POTENTIAL SHOCK HAZARD THAT MUST BE ELIMINATED BEFORE RETURNING THE UNIT TO THE CUSTOMER. B. Insulation Resistance Test Cold Check-(1) Unplug the power supply and connect a jumper wire between the two prongs of the plug. (2) Turn on the power switch of the unit. (3) Measure the resistance with an ohmmeter between the jumpered AC plug and each exposed metallic cabinet part on the unit. When testing 3 wire products, the resistance measured to the product enclosure should be between 2 and infinite Meg ohms. Also, the resistance measured to exposed output/ input connectors should be between 4 and infinite Meg ohms. When testing 2 wire products, the resistance measured to exposed output/input connectors should be between 4 and infinite Meg ohms. If it is not within the limits specified, there is the possibility of a shock hazard, and the unit must be repaired and rechecked before it is RETURNED TO THE CUSTOMER. ELECTROSTATIC DISCHARGE SENSITIVE (ESDS) DEVICE HANDLING This unit contains ESDS devices. We recommend the following precautions when repairing, replacing or transporting ESDS devices: - Perform work at an electrically grounded work station. Wear wrist straps that connect to the station or heel straps that connect to conductive floor mats. Avoid touching the leads or contacts of ESDS devices or PC boards even if properly grounded. Handle boards by the edges only. Transport or store ESDS devices in ESD protective bags, bins, or totes. Do not insert unpro- tected devices into materials such as plastic, polystyrene foam, clear plastic bags, bubble wrap or plastic trays. SAFETY INFORMATION CAUTION: THE BOSE ® PS 28 AND PS 35 POWERED SPEAKER CONTAINS NO USER-SER- VICEABLE PARTS. TO PREVENT WARRANTY INFRACTIONS, REFER SERVICING TO WARRANTY SERVICE STATIONS OR FACTORY SERVICE.