Sony wm ex 921 service manual

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2 WM-EX921 TABLE OF CONTENTS 1. SERVICING NOTES ............................................... 3 2. GENERAL ................................................................... 5 3. DISASSEMBLY 3-1. Disassembly Flow ........................................................... 6 3-2. Case Section .................................................................... 6 3-3. MAIN Board ................................................................... 7 3-4. Belt (F0) .......................................................................... 7 3-5. Motor, DC (Capstan/Reel) (M601) ................................. 8 3-6. Lid Assy, Cassette ........................................................... 8 3-7. Ornament (Open) Block Assy ......................................... 9 3-8. Holder (FA) Assy ............................................................ 9 3-9. Lever (N2) Assy, Pinch, Lever (R2) Assy, Pinch .... 10 3-10. Head, Magnetic (Playback) (HP901) ............................. 10 4. MECHANICAL ADJUSTMENTS ....................... 11 5. ELECTRICAL ADJUSTMENTS ......................... 11 6. DIAGRAMS 6-1. Block Diagram ................................................................ 13 6-2. Note for Printed Wiring Board and Schematic Diagrams ................................................ 14 6-3. Printed Wiring Board – MAIN Board (Component Side) – .............................. 16 6-4. Printed Wiring Board – MAIN Board (Conductor Side) – ................................ 17 6-5. Schematic Diagram – MAIN Board (1/2) – .................. 18 6-6. Schematic Diagram – MAIN Board (2/2) – .................. 19 6-7. IC Pin Function Description ........................................... 20 7. EXPLODED VIEWS 7-1. Cassette Lid Assy Section ............................................... 21 7-2. Case Section .................................................................... 22 7-3. MAIN Board Section ...................................................... 23 7-4. Mechanism Deck Section-1 (MT-WMEX921-162) ....... 24 7-5. Mechanism Deck Section-2 (MT-WMEX921-162) ....... 25 7-6. Mechanism Deck Section-3 (MT-WMEX921-162) ....... 26 8. ELECTRICAL PARTS LIST ............................... 27Notes on chip component replacement - Never reuse a disconnected chip component. - Notice that the minus side of a tantalum capacitor may be dam- aged by heat. Flexible Circuit Board Repairing - Keep the temperature of the soldering iron around 270 ˚C dur- ing repairing. - Do not touch the soldering iron on the same conductor of the circuit board (within 3 times). - Be careful not to apply force on the conductor when soldering or unsoldering. SAFETY-RELATED COMPONENT WARNING!! COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED LINE WITH MARK 0 ON THE SCHEMATIC DIAGRAMS AND IN THE PARTS LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUB- LISHED BY SONY. Note on the AC power adaptor Use only the supplied AC power adaptor. Do not use any other AC power adaptor. Polarity of the plug UNLEADED SOLDER Boards requiring use of unleaded solder are printed with the lead- free mark (LF) indicating the solder contains no lead. (Caution: Some printed circuit boards may not come printed with the lead free mark due to their particular size) : LEAD FREE MARK Unleaded solder has the following characteristics. - Unleaded solder melts at a temperature about 40 ˚C higher than ordinary solder. Ordinary soldering irons can be used but the iron tip has to be applied to the solder joint for a slightly longer time. Soldering irons using a temperature regulator should be set to about 350 ˚C . Caution: The printed pattern (copper foil) may peel away if the heated tip is applied for too long, so be careful! - Strong viscosity Unleaded solder is more viscous (sticky, less prone to flow) than ordinary solder so use caution not to let solder bridges occur such as on IC pins, etc. - Usable with ordinary solder It is best to use only unleaded solder but unleaded solder may also be added to ordinary solder.