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 PUBLISHED BY SONY.
BM-23MK2 SECTION 1 SERVICING NOTES This unit use PH501 (photo coupler) to detect reel rotation. As PH501 is mounted on the AUDIO board, reel rotation will not be detected if the AUDIO board has been removed. When performing mechanism deck operation and voltage checks whit the AUDIO board removed, perform them using the following method.
BM-23MK2 3-3. CONTROL PANEL BLOCK ASSEMBLY 1 screw (M1.4) control button assembly 4 lever (lock) AUDIO board 6 Remove the control panel block assembly in the direction of the arrow. 2 two claws 5 control button assembly 3 claw PRECAUTION DURING CONTROL PANEL BLOCK...
BM-23MK2 3-5. MECHANISM DECK (MB-23MK2-101) 3 two screws (M1.4 × 3.0) 1 Remove the soldering. lock plate assembly 2 Set the holder panel assembly to eject. shaft-A 4 mechanism deck note : When attaching the mechanism deck, (MB-23MK2-101) set the mechanism deck to stop and adjust the position of shaft-A and part A of the lock plate assembly.
BM-23MK2 SECTION 4 SECTION 5 MECHANICAL ADJUSTMENTS ELECTRICAL ADJUSTMENTS PRECAUTION PRECAUTION 1. Clean the following parts with a denatured-alcohol-moistened 1. Power supply voltage : 3V swab : playback head rubber belts Test Tape capstan idlers Type Signal Used for pinch roller 2.
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BM-23MK2 Tape Speed 2.4cm/s Adjustment Switch position TAPE SPEED Switch : 2.4 cm Procedure: frequency test counter WS-48A (3 kHz, 0 dB) 18 Ω J102 1. Play back WS-48A (tape center portion) in FWD mode. Adjust the RV602 so that the frequency counter reads 1,490±...
BM-23MK2 SECTION 6 DIAGRAMS • Note for Printed Wiring Boards and Schematic Diagrams Note on Printed Wiring Board: Note on Schematic Diagram: • X : parts extracted from the component side. • All capacitors are in µF unless otherwise noted. (p: pF) •...
BM-23MK2 • See page 12 for Waveform. • See page 21 for IC Pin Function Description. 6-7. SCHEMATIC DIAGRAM – LCD BOARD – S701 LCD701 R702 R701 470k 470k Q701 2SD1819A-R-TX Q712 Q713 UN5210-TX R722 UN5210-TX R703 R723 100k D702...
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BM-23MK2 • IC Block Diagrams — AUDIO Board — IC102, IC103 MM3111AWLE IC601 LB1979VS-TLM-E SHUTDOWN BIAS BYPASS SPEED CONTROL STARTING OSCILLATING REFERENCE VOLTAGE DETECT CIRCUIT WAVEFORM DETECT COMMUTATION STARTING LOGIC SPEED CURRENT IC502 MM1210-XFF DETECT DETECT POWER SOFT SWITCH SUPPLY...
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BM-23MK2 • IC Pin Function Description LCD BOARD IC701 SYSTEM CONTROLLER (BU2456-24) Pin No. Pin Name Description Reset terminal — GND terminal 1. When POWER IN becomes level “L”, UP counter, BATT, or LTR is displayed according to PHOTO IN change.
BM-23MK2 SECTION 7 EXPLODED VIEWS NOTE: • -XX and -X mean standardized parts, so they • The mechanical parts with no reference The components identified by mark 0 or may have some difference from the original number in the exploded views are not supplied.
BM-23MK2 SECTION 8 AUDIO ELECTRICAL PARTS LIST NOTE: • COILS uH: µH • Due to standardization, replacements in the When indicating parts by reference number, parts list may be different from the parts • RESISTORS please include the board name.
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BM-23MK2 AUDIO Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark C602 1-104-847-11 TANTAL. CHIP 22uF JR203 1-216-864-11 SHORT CHIP C603 1-104-847-11 TANTAL. CHIP 22uF JR204 1-216-296-11 SHORT CHIP C606 1-164-346-11 CERAMIC CHIP JR205 1-216-864-11 SHORT CHIP...
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BM-23MK2 REVISION HISTORY Clicking the version allows you to jump to the revised page. Also, clicking the version at the upper right on the revised page allows you to jump to the next revised page. Ver. Date Description of Revision...