Sony icf cd 855 v service manual

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2 ICF-CD855V About CD-Rs/CD-RWsThis 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 soft- ware. 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. 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. 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. 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 ËšC 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 ËšC. 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 viscou-s (sticky, less prone to flow) than ordinary solder so use caution not to let solder bridges oc- cur 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.

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3 ICF-CD855V TABLE OF CONTENTS 1. SERVICING NOTES .............................................. 3 2. GENERAL .................................................................. 4 3. DISASSEMBLY 3-1. Disassembly Flow........................................................... 5 3-2. Cabinet (Rear) Block...................................................... 5 3-3. Cabinet (Upper) Block.................................................... 6 3-4. CD Board......................................................................... 6 3-5. Optical Pick-up Block (KSM-900AAA)........................ 7 3-6. Optical Pick-up (KSS-900A).......................................... 7 3-7. MAIN Board................................................................... 8 3-8. Speaker (SP101/SP201).................................................. 9 3-9. CD Lid Block.................................................................. 9 4. TEST MODE .............................................................. 10 5. ELECTRICAL ADJUSTMENTS ........................ 13 6. DIAGRAMS 6-1. Block Diagram -“ CD Section -“.................................... 16 6-2. Block Diagram -“ TUNER Section -“............................ 17 6-3. Block Diagram -“ MAIN Section -“............................... 18 6-4. Note for Printed Wiring Boards and Schematic Diagrams....................................................... 19 6-5. Printed Wiring Boards -“ CD Section -“ ....................... 20 6-6. Schematic Diagram -“ CD Section -“............................. 21 6-7. Printed Wiring Board -“ TUNER Board -“..................... 22 6-8. Schematic Diagram -“ TUNER Board -“....................... 23 6-9. Printed Wiring Boards -“ PANEL Section -“................. 24 6-10. Printed Wiring Board -“ MAIN Section -“..................... 25 6-11. Schematic Diagram -“ MAIN Section (1/2) -“............... 26 6-12. Schematic Diagram -“ MAIN Section (2/2) -“............... 27 7. EXPLODED VIEWS 7-1. Overall Section................................................................ 33 7-2. Cabinet (Rear) Block Section......................................... 34 7-3. CD Lid Section................................................................ 35 7-4. LCD Section.................................................................... 36 7-5. Cabinet (Upper) Section................................................. 37 7-6. KEY Board Section......................................................... 38 7-7. Cabinet (Lower) Block Section...................................... 39 7-8. Speaker Section............................................................... 40 7-9. Optical Pick-up Section (KSM-900AAA)..................... 41 8. ELECTRICAL PARTS LIST .............................. 42The 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. SECTION 1 SERVICING NOTES NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK OR BASE UNIT -In performing the repair with the power supplied to the set, re- moving the MAIN board causes the set to be disabled. In such a case, short between 1 and 2 pins of the W604 on the MAIN board using a lead wire. 21 -“ MAIN Board (Conductor Side) -“ W604