Sony icf cd 843 v service manual

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2 ICF-CD843V About CD-Rs/CD-RWs This unit is compatible with CD-Rs/CD-RWs but playback capability may vary depending on the quality of the disc, the recording device and application software. TABLE OF CONTENTS 1. SERVICING NOTES .............................................. 3 2. GENERAL .................................................................. 4 3. DISASSEMBLY 3-1. Disassembly Flow........................................................... 5 3-2. Rear Cabinet Assy........................................................... 6 3-3. CD Lid............................................................................. 6 3-4. Upper Cabinet Assy........................................................ 7 3-5. MAIN Board................................................................... 7 3-6. CD Block......................................................................... 8 3-7. Optical Pick-up (KSS-213R).......................................... 8 4. ELECTRICAL ADJUSTMENTS Tuner Section................................................................. 9 CD Section..................................................................... 11 5. DIAGRAMS 5-1. Block Diagram -“ CD Section -“.................................... 12 5-2. Block Diagram -“ MAIN Section -“............................... 13 5-3. Note for Printed Wiring Board and Schematic Diagrams....................................................... 14 5-4. Printed Wiring Board -“ CD Section -“.......................... 16 5-5. Schematic Diagram -“ CD Section -“............................. 17 5-6. Printed Wiring Board -“ MAIN Section -“..................... 18 5-7. Printed Wiring Boards -“ POWER Section -“................ 19 5-8. Schematic Diagram -“ MAIN section (1/2) -“............... 20 5-9. Schematic Diagram -“ MAIN section (2/2) -“............... 21 5-10. Printed Wiring Boards -“ PANEL Section -“................. 22 5-11. Schematic Diagram -“ PANEL Section -“...................... 23 6. EXPLODED VIEWS 6-1. Cabinet Section............................................................... 27 6-2. Upper Cabinet Section.................................................... 28 6-3. Front Cabinet Section..................................................... 29 6-4. Rear Cabinet Section...................................................... 30 6-5. Optical Pick-up Section (KSM-213RDP)...................... 31 7. ELECTRICAL PARTS LIST .............................. 32 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. SAFETY CHECK-OUT After correcting the original service problem, perform the follow- ing safety check before releasing the set to the customer: Check the antenna terminals, metal trim, metallized knobs, screws, and all other exposed metal parts for AC leakage. Check leakage as described below. LEAKAGE TEST The AC leakage from any exposed metal part to earth ground and from all exposed metal parts to any exposed metal part having a return to chassis, must not exceed 0.5 mA (500 microamperes). Leakage current can be measured by any one of three methods. 1. A commercial leakage tester, such as the Simpson 229 or RCA WT-540A. Follow the manufacturers instructions to use these instruments. 2. A battery-operated AC milliammeter. The Data Precision 245 digital multimeter is suitable for this job. 3. Measuring the voltage drop across a resistor by means of a VOM or battery-operated AC voltmeter. The limit indica- tion is 0.75 V, so analog meters must have an accurate low- voltage scale. The Simpson 250 and Sanwa SH-63Trd are ex- amples of a passive VOM that is suitable. Nearly all battery operated digital multimeters that have a 2 V AC range are suit- able. (See Fig. A) Fig. A. Using an AC voltmeter to check AC leakage. 1.5 k -„¦ 0.15 µF AC voltmeter (0.75 V) To Exposed Metal Parts on Set Earth Ground CAUTION Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous ra- diation exposure. Notes 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 ËšC 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.

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3 ICF-CD843V S302 SECTION 1 SERVICING NOTES The laser diode in the optical pick-up block may suffer electro- static break-down because of the potential difference generated by the charged electrostatic load, etc. on clothing and the human body. During repair, pay attention to electrostatic break-down and also use the procedure in the printed matter which is included in the repair parts. The flexible board is easily damaged and should be handled with care. NOTES ON LASER DIODE EMISSION CHECK The laser beam on this model is concentrated so as to be focused on the disc reflective surface by the objective lens in the optical pick-up block. Therefore, when checking the laser diode emis- sion, observe from more than 30 cm away from the objective lens. LASER DIODE AND FOCUS SEARCH OPERATION CHECK During normal operation of the equipment, emission of the laser diode is prohibited unless the upper lid is closed while turning ON the S302. (push switch type) The following checking method for the laser diode is operable. -Method Emission of the laser diode is visually checked. 1. Open the upper lid. 2. Push the S302 as shown in Fig.1. Note: Do not push the detection lever strongly, or it may be bent or dam- aged. 3. Press the CD u button. 4. Check the object lens for confirming normal emission of the laser diode. If not emitting, there is a trouble in the automatic power control circuit or the optical pick-up. In this operation, the object lens will move up and down 2 times along with inward motion for the focus search. NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK OR BASE UNIT CHUCK PLATE JIG ON REPAIRING On repairing CD section, playing a disc without the CD lid, use Chuck Plate Jig. -Code number of Chuck Plate Jig: X-4918-255-1 Fig.1 Method to push the S302