Jvc-KDS-790-Service-Manual(1) 电路图 维修手册.pdf

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1、SERVICE MANUAL COPYRIGHT 2002 VICTOR COMPANY OF JAPAN, LTD. No.49788 2003/02 KD-S790 CD RECEIVER 49788200302 KD-S790 TABLE OF CONTENTS 1Important Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 2Disassembly

2、method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 3Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3、. 1-23 4Description of major ICs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-27 COMPACT DIGITAL AUDIO S Area Suffix J - - - - - - - - - - - Northern America RadioFans.CN 收音机爱 好者资料库 KD-S790 1-2 (No.49788) SECTION 1 Imp

4、ortant Safety Precautions 1.1 Safety Precautions ! Burrs formed during molding may be left over on some parts of the chassis. Therefore, pay attention to such burrs in the case of preforming repair of this system. ! Please use enough caution not to see the beam directly or touch it in case of an adj

5、ustment or operation check. RadioFans.CN 收音机爱 好者资料库 KD-S790 (No.49788)1-3 1.2 Preventing static electricity Electrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is discharged, can destroy the laser diode in the traverse unit (optical pickup). Take care

6、 to prevent this when performing repairs. 1.2.1 Grounding to prevent damage by static electricity Static electricity in the work area can destroy the optical pickup (laser diode) in devices such as DVD players. Be careful to use proper grounding in the area where repairs are being performed. (1) Gro

7、und the workbench Ground the workbench by laying conductive material (such as a conductive sheet) or an iron plate over it before placing the traverse unit (optical pickup) on it. (2) Ground yourself Use an anti-static wrist strap to release any static electricity built up in your body. (3) Handling

8、 the optical pickup In order to maintain quality during transport and before installation, both sides of the laser diode on the replacement optical pickup are shorted. After replacement, return the shorted parts to their original condition. (Refer to the text.) Do not use a tester to check the condi

9、tion of the laser diode in the optical pickup. The testers internal power source can easily destroy the laser diode. 1.3 Handling the traverse unit (optical pickup) (1) Do not subject the traverse unit (optical pickup) to strong shocks, as it is a sensitive, complex unit. (2) Cut off the shorted par

10、t of the flexible cable using nippers, etc. after replacing the optical pickup. For specific details, refer to the replacement procedure in the text. Remove the anti-static pin when replacing the traverse unit. Be careful not to take too long a time when attaching it to the connector. (3) Handle the

11、 flexible cable carefully as it may break when subjected to strong force. (4) I t is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not turn it. 1.4 Attention when traverse unit is decomposed *Please refer to Disassembly method in the text for the CD pickup unit. App

12、ly solder to the short land before the flexible wire is disconnected from the connector on the CD pickup unit. (If the flexible wire is disconnected without applying solder, the CDpickup may be destroyed by static electricity.) In the assembly, be sure to remove solder from the short land after conn

13、ecting the flexible wire. 1M (caption) Anti- static wrist strap Conductive material (conductive sheet) or iron plate Pickup Short- circuit point (Soldering) Flexible wire PickupShort- circuit point RadioFans.CN 收音机爱 好者资料库 KD-S790 1-4 (No.49788) SECTION 2 Disassembly method 2.1 Main body 2.1.1Removin

14、g the front panel assembly (See Fig.1) (1) Push the detach button in the lower left part of the front panel assembly and remove the front panel assembly in the direction of the arrow. Fig.1 2.1.2Removing the front chassis assembly (See Figs.2 to 4) Prior to performing the following procedure, remove

15、 the front panel assembly. (1) Remove the screw A on the both sides of the main body, and two screws B on the front chassis assembly. (2) Release the two joints a and the two joints b on both sides of the main body using a screwdriver, and remove the front chassis assembly forward. Fig.2 Fig.3 Fig.4

16、 Front panel assembly Detach button Joint a Joint a Front chassis assembly A Front chassis assembly Joint b Joint b A B KD-S790 (No.49788)1-5 2.1.3Removing the heat sink (See Fig.5) (1) Remove the two screws C and two screws D on the left side of the main body. Fig.5 2.1.4Removing the bottom cover (

17、See Figs.6 and 7) Prior to performing the following procedure, remove the front panel assembly, front chassis assembly and heat sink. (1) Turn over the body and release the two joints c, two joints d and joint e. CAUTION: Do not damage the main board when releasing the joint e us- ing a screwdriver.

18、 (See Figs.6 and 7) Fig.6 Fig.7 2.1.5Removing the rear bracket (See Fig.8) Prior to performing the following procedure, remove the front panel assembly, front chassis assembly, heat sink and bottom cover. (1) Remove the three screws E, three screws F and two screws G on the back of the body. (2) Rem

19、ove the rear bracket. Fig.8 C D Heat sink Joint c Joint d Joint e Bottom cover Joint d Joint c Joint e Bottom cover FG EEF Rear bracket KD-S790 1-6 (No.49788) 2.1.6Removing the main board (See Fig.9) Prior to performing the following procedure, remove the front panel assembly, front chassis assembly

20、, heat sink, bottom cover and rear bracket. (1) Remove the two screws H attaching the main board. (2) Disconnect connector CN501 and remove the main board. Fig.9 2.1.7Removing the CD mechanism assembly (See Fig.10) Prior to performing the following procedure, remove the front panel assembly, front c

21、hassis assembly, heat sink, bottom cover, rear bracket and main board. (1) Remove the three screws J . Fig.10 Main board H H CN501 J J CD mechanism assembly Top chassis KD-S790 (No.49788)1-7 2.1.8Removing the front board (See Figs.11 to 13) Prior to performing the following procedure, remove the fro

22、nt panel assembly. (1) Remove the four screws K on the back side of the front panel assembly. (2) Release the ten joints f . (3) Take out the front board. Fig.11 Fig.12 Fig.13 KK K Joint f Joint f Joint f Joint f Front board KD-S790 1-8 (No.49788) 2.2 CD Mechanism Assembly 2.2.1Removing the top cove

23、r (See Figs.1 and 2) (1) Remove the two screws A on the both side of the body. (2) Lift the front side of the top cover and move the top cover backward to release the two joints a. Fig.1 Fig.2 A A A Joints aTop cover Joints a Top cover KD-S790 (No.49788)1-9 2.2.2Removing the connector board (See Fig

24、s.3 to 5) CAUTION: Before disconnecting the flexible wire from the pickup, solder the short-circuit point on the pickup. No observance of this in- struction may cause damage of the pickup. (1) Remove the screw B fixing the connector board. (2) Solder the short-circuit point on the connector board. (

25、3) Disconnect the flexible wire from the pickup. (4) Move the connector board in the direction of the arrow to release the two joints b. (5) Unsolder the wire on the connector board if necessary. CAUTION: Unsolder the short-circuit point after reassembling. Fig.3 Fig.4 Fig.5 B Connector board Pickup

26、Short- circuit point Joints b Wires Pickup Short- circuit point (Soldering) Flexible wire B Flexible wire Connector board Frame KD-S790 1-10 (No.49788) 2.2.3Removing the DET switch (See Figs.6 and 7) (1) Extend the two tabs c of the feed sw. holder and pull out the switch. (2) Unsolder the DET switc

27、h wire if necessary. Fig.6 Fig.7 Connector board DET switch Pickup DET switch Tab c Tab c DET switch wire Feed sw. holder KD-S790 (No.49788)1-11 2.2.4Removing the chassis unit (See Figs.8 and 9) Prior to performing the following procedure, remove the top cover and connector board. (1) Remove the two

28、 suspension springs (L) and (R) attaching the chassis unit to the frame. CAUTION: The shape of the suspension spring (L) and (R) are dif- ferent. Handle them with care. When reassembling, make sure that the three shafts on the underside of the chassis unit are inserted to the dampers certainly. Fig.

29、8 Fig.9 Suspension spring (L) Suspension spring (L) Suspension spring (R) Suspension spring (R) Chassis unit Frame Chassis unit Frame Shafts Shaft Damper Damper Damper KD-S790 1-12 (No.49788) 2.2.5Removing the clamper assembly (See Figs.10 and 11) Prior to performing the following procedure, remove

30、the top cover. (1) Remove the clamper arm spring. (2) Move the clamper assembly in the direction of the arrow to release the two joints d. Fig.10 Fig.11 Clamper arm spring Chassis rivet assembly Joint d Joint d Clamper assembly Clamper arm spring Clamper assembly Joint d Joint d Chassis rivet assemb

31、ly KD-S790 (No.49788)1-13 2.2.6Removing the loading / feed motor assembly (See Figs.12 and 13) Prior to performing the following procedure, remove the top cover, connector board and chassis unit. (1) Remove the screw C and move the loading / feed motor assembly in the direction of the arrow to remov

32、e it from the chassis rivet assembly. (2) Disconnect the wire from the loading / feed motor assembly if necessary. CAUTION: When reassembling, connect the wire from the loading / feed motor assembly to the flame as shown in Fig.12. Fig.12 Fig.13 Loading / feed motor assembly Loading / feed motor ass

33、embly C KD-S790 1-14 (No.49788) 2.2.7Removing the pickup unit (See Figs.14 to 18) Prior to performing the following procedure, remove the top cover, connector board and chassis unit. (1) Remove the screw D and pull out the pu. shaft holder from the pu. shaft. (2) Remove the screw E attaching the fee

34、d sw. holder. (3) Move the part e of the pickup unit upward with the pu. shaft and the feed sw. holder, then release the joint f of the feed sw. holder in the direction of the arrow. The joint g of the pickup unit and the feed rack is released, and the feed sw. holder comes off. (4) Remove the pu. s

35、haft from the pickup unit. (5) Remove the screw F attaching the feed rack to the pickup unit. 2.2.8Reattaching the pickup unit (See Figs.14 to 17) (1) Reattach the feed rack to the pickup unit using the screw F. (2) Reattach the feed sw. holder to the feed rack while setting the joint g to the slot

36、of the feed rack and setting the part f of the feed rack to the switch of the feed sw. holder correct- ly. (3) As the feed sw. holder is temporarily attached to the pickup unit, set to the gear of the joint g and to the bending part of the chassis (joint h) at a time. CAUTION: Make sure that the par

37、t i on the underside of the feed rack is certainly inserted to the slot j of the change lock lever. (4) Reattach the feed sw. holder using the screw E. (5) Reattach the pu. shaft to the pickup unit. Reattach the pu. shaft holder to the pu. shaft using the screw D. Fig.14 Fig.15 Fig.16 Fig.17 Fig.18

38、Feed sw. holder E D Joint g Joint f Part e Pickup unit Pu. shaft holder Pu. shaft Feed sw. holder Part e Pickup unit Feed rack Feed sw. holder D E Joint f Pu. shaft holder Pu. shaft Pickup unit Joint h Part i Slot j Joint g FFeed rack Pickup unit Joint f Joint g Feed rack Pickup unit Feed sw. holder

39、 KD-S790 (No.49788)1-15 2.2.9Removing the trigger arm (See Figs.19 and 20) Prior to performing the following procedure, remove the top cover, connector board and clamper unit. (1) Turn the trigger arm in the direction of the arrow to release the joint k and pull out upward. CAUTION: When reassemblin

40、g, insert the part m and n of the trigger arm into the part p and q at the slot of the chassis rivet assembly respectively and join the joint k at a time. Fig.19 Fig.20 2.2.10 Removing the top plate assembly (See Fig.21) Prior to performing the following procedure, remove the top cover, connector bo

41、ard, chassis unit, and clamper assembly. (1) Remove the screw H. (2) Move the top plate assembly in the direction of the arrow to release the two joints r. (3) Unsolder the wire marked s if necessary. Fig.21 Joint k Trigger arm Chassis rivet assembly Trigger arm Chassis rivet assembly Part p Part m

42、Part n Part q Top plate assembly Joints r s H KD-S790 1-16 (No.49788) 2.2.11 Removing the mode sw. / select lock arm (See Figs.22 and 23) Prior to performing the following procedure, remove the top plate assembly. (1) Bring up the mode sw. to release from the link plate (joint t) and turn in the dir

43、ection of the arrow to release the joint u. (2) Unsolder the wire of the mode sw. marked s if necessary. (3) Turn the select lock arm in the direction of the arrow to re- lease the two joints v. (4) The select lock arm spring comes off the select lock arm at the same time. Fig.22 Fig.23 Mode sw. Sel

44、ect lock arm Joint tLink plate Joint u s Top plate Top plate Select lock arm Select lock arm spring Select lock arm Link plate Joints v Hook w KD-S790 (No.49788)1-17 2.2.12 Reassembling the mode sw. / select lock arm (See Figs.24 to 26) REFERENCE: Reverse the above removing procedure. (1) Reattach t

45、he select lock arm spring to the top plate and set the shorter end of the select lock arm spring to the hook w on the top plate. (2) Set the other longer end of the select lock arm spring to the boss x on the underside of the select lock arm, and join the select lock arm to the slots (joint v). Turn

46、 the select lock arm as shown in the figure. (3) Reattach the mode sw. while setting the part t to the first peak of the link plate gear, and join the joint u. CAUTION: When reattaching the mode sw., check if the points y and z are correctly fitted and if each part operates properly. Fig.24 Fig.25 F

47、ig.26 Select lock arm Hook w Boss x Select lock arm spring Joint v Joint v Link plate Joint t Point z Point y Select lock arm Mode sw. Joint t Joint u Link plate KD-S790 1-18 (No.49788) 2.2.13 Removing the select arm R / link plate (See Figs.27 and 28) Prior to performing the following procedure, re

48、move the top plate assembly. (1) Bring up the select arm R to release from the link plate (joint a) and turn as shown in the figure to release the two joints b and joint c. (2) Move the link plate in the direction of the arrow to release the joint d. Remove the link plate spring at the same time. RE

49、FERENCE: Before removing the link plate, remove the mode sw. Fig.27 Fig.28 2.2.14 Reattaching the Select arm R / link plate (See Figs.29 and 30) REFERENCE: Reverse the above removing procedure. (1) Reattach the link plate spring. (2) Reattach the link plate to the link plate spring while joining them at joint d. (3) Reattach the joint a of the select arm R to the first peak of the link plate while joining the two joints b with the slots. Then turn the select arm R as shown in the figure. The top plate is joined to the joint c. CAUTION: When reatta