Sony hcd gx 250 service manual
This is the 64 pages manual for sony hcd gx 250 service manual.
Read or download the pdf for free. If you want to contribute, please upload pdfs to audioservicemanuals.wetransfer.com.
Extracted text from sony hcd gx 250 service manual (Ocr-read)
Page 1
2 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 PUBLISHED BY SONY. ATTENTION AU COMPOSANT AYANT RAPPORT À LA SÉCURITÉ! LES COMPOSANTS IDENTIFÉS PAR UNE MARQUE 0 SUR LES DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT. NE REMPLACER CES COMPOSANTS QUE PAR DES PIÈSES SONY DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU D ANS LES SUPPÉMENTS PUBLIÉS PAR SONY. After correcting the original service problem, perform the following safety checks before releasing the set to the customer: Check the antenna terminals, metal trim, metallized knobs, screw\ s, and all other exposed metal parts for AC leakage. Check leakage as described below. LEAKAGE 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 indication is 0.75 V, so analog meters must have an accurate low-voltage scale. The Simpson 250 and Sanwa SH-63Trd are examples of a passive VOM that is suitable. Nearly all battery operated digital multimeters that have a 2V AC range are suitable. (See Fig. A) SAFETY CHECK-OUT HCD-GX250 The release method of a CD disc tray LOCK function There is a disc lock function for the disc theft prevention for a demonstration at a shop front in this machine. Procedue: 1. Press the ?/1 button to turn the set on. 2. Press two buttons of x and Z (EJECT) simultaneously for fi ve seconds. 3. The message LOCKED is displayed and the tray is locked. (Even if exiting from this mode, the tray is still locked.) 4. Press two buttons of x and Z (EJECT) simultaneously for fi ve seconds again. 5. The message UNLOCKED is displayed and the tray is unlocked. 6. To exit from this mode, press the ?/1 b utton to turn the set off. To Exposed Metal Par ts on Set 0.15 µF 1.5 kΩ AC V oltmeter (0.75 V) Earth Ground Fig. A. Using an AC voltmeter to check AC leakage. 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.
Page 2
3 HCD-GX250 This appliance is classified as a CLASS 1 LASER product. The CLASS 1 LASER PRODUCT MARKING is located on the rear exterior. Laser component in this product is capable of emitting radiation exceeding the limit for Class 1. CAUTION Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure. Notes on chip component replacement -N ever reuse a disconnected chip component. - Notice that the minus side of a tantalum capacitor may be damaged by heat. Flexible Circuit Board Repairing -K eep the temperature of soldering iron around 270˚C during 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. NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK OR BASE UNIT The laser diode in the optical pick-up block may suffer electrostatic 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 emission, observe from more than 30 cm away from the objective lens. T ABLE OF CONTENTS 1. SERVICING NOTE ··················\ ··················\ ··················\ ···· 4 2. GENERAL ··················\ ··················\ ··················\ ··················\ ·· 6 3. DISASSEMBLY 3-1. Cover (Top) ··················\ ··················\ ··················\ ··············· 9 3-2. CD Door ··················\ ··················\ ··················\ ··················\ ·· 9 3-3. Front Panel Section ··················\ ··················\ ··················\ · 10 3-4. CD Mechanism Deck (CDM74-K6BD80) ··················\ · 10 3-5. Tape Mechanism Deck, GAME JACK Board ··············· 11 3-6. PANEL Board ··················\ ··················\ ··················\ ········· 11 3-7. BACK PANEL Section, SUB-TRANS Board ·············· 12 3-8. Power Transformer ··················\ ··················\ ··················\ · 12 3-9. MAIN Board ··················\ ··················\ ··················\ ··········· 13 3-10. AMP Board ··················\ ··················\ ··················\ ··········· 13 3-11. BD80A Board ··················\ ··················\ ··················\ ······· 14 3-12. CONNECT Board ··················\ ··················\ ··················\ · 14 3-13. DRIVER Board, SW Board ··················\ ··················\ ···· 15 3-14. Optical Pick-up (KSM-213DCP/Z-NP) ··················\ ···· 15 3-15. SENSOR Board ··················\ ··················\ ··················\ ···· 16 3-16. MOTOR (TB) Board ··················\ ··················\ ··············· 16 3-17. MOTOR (LD) Board ··················\ ··················\ ·············· 17 4. TEST MODE ··················\ ··················\ ··················\ ·············· 18 5. DIAGRAMS 5-1. Block Diagrams – PANEL Section – ··················\ ·········· 22 – MAIN Section – ··················\ ··················\ ··················\ · 23 – BD/DRIVER Section – ··················\ ··················\ ········ 24 5-2. Printed Wiring Board – BD80A Section – ··················\ ·· 25 5-3. Schematic Diagram – BD80A Section – ··················\ ···· 26 5-4. Printed Wiring Board – CD MECHANISM Section – · 27 5-5. Schematic Diagram – CD MECHANISM Section – ···· 28 5-6. Printed Wiring Board – MAIN Section – ··················\ ··· 29 5-7. Schematic Diagram – MAIN Section (1/2) – ··············· 30 5-8. Schematic Diagram – MAIN Section (2/2) – ··············· 31 5-9. Printed Wiring Board – PANEL COMB Section – ······· 32 5-10. Schematic Diagram – PANEL COMB Section – ······· 33 5-11. Printed Wiring Board – PANEL Section – ··················\ 34 5-12. Schematic Diagram – PANEL Section (1/2) – ··········· 35 5-13. Schematic Diagram – PANEL Section (2/2) – ··········· 36 5-14. Printed Wiring Board – TRANS Section – ················· 37 5-15. Printed Wiring Board – AMP Section – ··················\ ···· 38 5-16. Schematic Diagram – AMP POWER Section – ········· 39 5-17. IC Pin Function Description ··················\ ··················\ ··· 41 6. EXPLODED VIEWS 6-1. MAIN Section ··················\ ··················\ ··················\ ········· 46 6-2. Front Panel Section ··················\ ··················\ ··················\ · 47 6-3. MAIN Board Section ··················\ ··················\ ················ 48 6-4. CD Mechanism Deck Section -1 (CDM74-K6BD80) ·· 49 6-4. CD Mechanism Deck Section -2 (CDM74-K6BD80) ·· 50 7. ELECTRICAL PARTS LIST ··················\ ··················\ ··· 51