Jvc-KSFX-281-Service-Manual(1) 电路图 维修手册.pdf

SERVICE MANUAL COPYRIGHT 2003 VICTOR COMPANY OF JAPAN, LIMITED No.49869 2003/10 CASSETTE RECEIVER 49869200310 KS-FX281 TABLE OF CONTENTS 1PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 2SPECIFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 3DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5 4Adjustment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13 5TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17 Area Suffix UF - China SCMMO/RND S.BASS SEL AM FM DISP CH CD SSM 789101112 RadioFans.CN 收音机爱 好者资料库 1-2 (No.49869) SPECIFICATION Design and specifications are subject to change without notice. AUDIO AMPLIFIER SECTION Maximum Power OutputFront45 W per channel Rear45 W per channel Continuous Power Output (RMS) Front17 W per channel into 4 40 Hz to 20 000 Hz at no more than 0.8% total harmonic distortion. Rear17 W per channel into 4 40 Hz to 20 000 Hz at no more than 0.8% total harmonic distortion. Load Impedance4 (4 to 8 allowance) Tone Control RangeBass10 dB at 100 Hz Treble10 dB at 10 kHz Frequency Response40 Hz to 20 000 Hz Signal-to-Noise Ratio70 dB Line-Out Level/Impedance2.0 V/20 k load (250 nWb/m) TUNER SECTION Frequency RangeFM87.5 MHz to 108.0 MHz AM531 kHz to 1 602 kHz FM TunerUsable Sensitivity11.3 dBf (1.0 V/75 ) 50 dB Quieting Sensitivity 16.3 dBf (1.8 V/75 ) Alternate Channel Selectivity (400 kHz) 65 dB Frequency Response 40 Hz to 15 000 Hz Stereo Separation35 dB Capture Ratio2.0 dB AM TunerSensitivity20 V Selectivity35 dB CASSETTE DECK SECTION Wow & Flutter0.15% (WRMS) Fast-Wind Time190 sec. (C-60) Frequency Response50 Hz to 14 000 Hz(Normal tape) Signal-to-Noise Ratio52 dB Stereo Separation40 dB GENERAL Power RequirementOperating VoltageDC 14.4 V(11 V to 16 V allowance) Grounding SystemNegative ground Allowable Operating Temperature0C to +40C Dimensions (W H D)Installation Size (approx.)182 mm 52 mm 150 mm Panel Size (approx.)188 mm 58 mm 11 mm Mass (approx.)1.3 kg (excluding accessories) RadioFans.CN 收音机爱 好者资料库 (No.49869)1-3 SECTION 1 PRECAUTION 1.1Safety 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. RadioFans.CN 收音机爱 好者资料库 1-4 (No.49869) SECTION 2 SPECIFIC SERVICE INSTRUCTIONS This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS. (No.49869)1-5 SECTION 3 DISASSEMBLY 3.1Main body 3.1.1Removing the front panel assembly (See Fig.1) (1) Press the release button and remove the front panel assembly. Fig.1 3.1.2Removing the bottom cover (See Fig.2) Prior to performing the following procedure, remove the front panel assembly. (1) Turn the body upside down. (2) Insert a screwdriver under the joints to release the two joints a on the left side, the two joints b on the right side and the joint c on the back of the body, then remove the bottom cover from the body. CAUTION: When releasing the joint c using a screwdriver, do not damage the board. Fig.2 3.1.3Removing the front chassis (See Fig.3) Prior to performing the following procedure, remove the front panel assembly and bottom cover. (1) Remove the two screws A on each side of the body. (2) Release the two joints d and the two joints e on the sides, then remove the front chassis toward the front. Fig.3 Front panel assembly Release button Bottom cover Joint b Joint b Joint c Joint a Joint a Joint d Front chassis A Joint e Joint dJoint e 1-6 (No.49869) 3.1.4Removing the heat sink (See Fig.4) Prior to performing the following procedure, remove the front panel assembly. (1) Remove the screw B and two screws C attaching the heat sink on the left side of the body, and remove the heat sink. Fig.4 3.1.5Removing the rear panel (See Fig.5) Prior to performing the following procedure, remove the front panel assembly and bottom cover. (1) Remove the two screws D, two screws E and three screws F attaching the rear panel on the back of the body. Fig.5 3.1.6Removing the main board (See Fig.6) Prior to performing the following procedure, remove the front panel assembly, bottom cover, front chassis, heat sink and rear panel. (1) Remove the two screws G attaching the main board on the top chassis. (2) Disconnect the two connectors CN901 and CN721 on the main board from the cassette mechanism assembly. Fig.6 Heat sink CBC D E DFFE G G Main board CN901 CN721 (No.49869)1-7 3.1.7Removing the cassette mechanism assembly (See Fig.7) Prior to performing the following procedure, remove the front panel assembly, bottom cover, front chassis, heat sink, rear panel and main board. (1) Remove the four screws H attaching the cassette mecha- nism assembly from the top chassis. Fig.7 3.1.8Removing the head amplifier board (See Fig.8) Prior to performing the following procedure, remove the front panel assembly, bottom cover, front chassis, heat sink, rear panel, main board and cassette mechanism assembly. (1) Disconnect the wire from CJ901 on the head amplifier board. (2) Remove the one screw J attaching the head amplifier board. (3) Move the head amplifier board in the direction of the arrow to release the two joints f, the head amplifier board can be removed. Fig.8 3.1.9Removing the relay board (See Fig.9) Prior to performing the following procedure, remove the front panel assembly, bottom cover, front chassis, heat sink, rear panel, main board and cassette mechanism assembly. (1) Disconnect the wire from CP722 on the relay board. (2) Remove the one screw K attaching the relay board. (3) Move the relay board in the direction of the arrow to release the joint g, the relay board can be removed. Fig.9 H H HH Top chassis Cassette mechanism assembly J CJ901 Head amplifier board Joint f Joint f To head relay board K CP722Relay board Joint g 1-8 (No.49869) 3.1.10 Removing the mecha bracket (See Fig.10) Prior to performing the following procedure, remove the front panel assembly, bottom cover, front chassis, heat sink, rear panel, main board, cassette mechanism assembly, head am- plifier board and relay board. (1) Remove the four screws L attaching the mecha bracket. Fig.10 3.1.11 Removing the switch (LCD & key) board (See Fig.11 to 13) Prior to performing the following procedure, remove the front panel assembly. (1) Remove the four screws M attaching the rear cover on the back of the front panel assembly. (2) Release the eleven joints h, the front panel and the rear cover become separate. (3) Remove the switch board from the rear cover. Fig.11 Fig.12 Fig.13 Mecha bracket L L L L M MM M Joint h Joint h Joint h Joint h Switch (LCD & Key) board (No.49869)1-9 3.2Cassette mechanism assembly Prior to performing the following procedures, remove the head amplifier board, the relay board and the mechanism bracket. 3.2.1Removing the direction switch board (See Fig.1) (1) Unsolder the three wires a on the direction switch board. (2) Remove the one screw A attaching the direction switch board. 3.2.2Removing the FF / REW lever assembly (See Fig.1) (1) Remove the screw B attaching the FF / REW lever assem- bly on the back of the cassette mechanism assembly. (2) Remove the screw C on the upper side of the FF / REW lever assembly. (3) Lift and pull forward the FF / REW lever assembly to disen- gage the joints b, c, d and e. 3.2.3Reattaching the FF / REW lever assembly (See Fig.1) (1) Reattach the FF / REW lever assembly to the joint c on the back of the chassis. (2) Reattach the pinch-roller shaft e, the change lever d and the return link e to the chassis. Fig.1 3.2.4Removing the playback head (See Fig.2) Prior to performing the following procedure, remove the direc- tion switch board and the FF / REW lever assembly. (1) Remove the screw D attaching the playback head. (2) Remove the C washer and pull out the FF roller. (3) Remove the S support plate, the A arm spring (a) and (b), the playback head. ATTENTION: The A arm spring (a) differs from the A arm spring (b). 3.2.5Removing the pinch-roller (R) and (F) assembly (See Fig.2) Prior to performing the following procedure, remove the direc- tion switch board and the FF / REW lever assembly. (1) Remove the P arm spring (f) in the pinch-roller (F) assem- bly from the chassis. (2) Remove the P arm spring (r) in the pinch-roller (R) assem- bly from the chassis. (3) Draw out the pinch roller (F) and (R) assembly from the shaft. ATTENTION: The P arm spring (f) differs from the P arm spring (r). ATTENTION: The pinch roller (F) assembly differs from the pinch roller (R) assembly. Fig.2 C FF / REW lever assembly Joint c Joint b B A Direction switch board Joint d Joint e Soldering a A arm spring (b) A arm spring (a) Pinch-roller (R) assembly Pinch-roller (F) assembly Shaft Shaft S support plate D C washer P arm spring (f)P arm spring (r) Remove the P arm spring (f) from the chassis. Remove the P arm spring (r) from the chassis. Playback head FF roller 1-10 (No.49869) 3.2.6Removing the cassette hanger / cassette holder (See Fig.3) Prior to performing the following procedure, remove the FF / REW lever assembly. (1) From the rear of the unit, bend the two tabs f outwards and disengage the two joints g in the direction of the arrow. (2) Push the eject lever and remove the cassette holder from the playback head. Disengage the two joints h of the cas- sette hanger / cassette holder and the eject lever in the di- rection of the arrow. (3) Lift the cassette hanger / cassette holder and disengage the joint i of the return link and the eject lever. Fig.3 3.2.7Removing the reel disc assembly (See Fig.4) Prior to performing the following procedure, remove the FF / REW lever assembly and the cassette hanger / cassette hold- er. (1) Remove the C washer and pull out reel disc assembly. ATTENTION: Replace with a new C washer when reattaching. Fig.4 3.2.8Removing the motor assembly (See Fig.5) (1) Unsolder the two wires j on the motor assembly. (2) Turn over the cassette mechanism assembly and remove the main belt and the sub-belt from the motor pulley. ATTENTION: The main belt can now be removed. (3) Remove the two screws G attaching the motor assembly. Fig.5 Cassette holder Cassette hanger Return link Joint i Eject lever Joint h Joint h Joint g Joint g Tab f Tab f Chassis Reel disc assembly C washer C washer Flywheel (BF) Flywheel (BR) E E E F G G Main-belt Reel base assembly Sub-belt Motor assembly Motor pulley Soldering j (No.49869)1-11 3.2.9Removing the Flywheel (BF) and (BR) assembly (See Fig.4 and 5) Prior to performing the following procedure, remove the cas- sette hanger / cassette holder. (1) From the upper side of the cassette mechanism assembly, remove the C washer from each shaft of the flywheel (BF) and (BR). (2) Turn over the cassette mechanism assembly and remove the main belt. Pull out the flywheel (BF) and (BR) down- ward respectively. Fig.4 Fig.5 3.2.10 Removing the reel base assembly (See Fig.5 and 6) (1) Raise the part k of the reel base assembly slightly and re- move the selector link (B) on the front side of the cassette mechanism assembly by turning it as shown in Fig.6. (2) Remove the three screws E and the one screw F on the underside of the cassette mechanism assembly. ATTENTION: The reel base assembly is not repairable. Handle with care. Fig.6 Fig.7 Reel disc assembly C washer C washer Flywheel (BF) Flywheel (BR) E E E F G G Main-belt Reel base assembly Sub-belt Motor assembly Motor pulley Soldering j Selector link (B). Pinch-roller (R) assembly Turn the selector link (B). k Inside of the reel base assembly 1-12 (No.49869) 3.2.11 Removing the mute switch board (See Fig.8) (1) Unsolder the two wires l on the mute switch board on the back of the cassette mechanism assembly. (2) Remove the screw H attaching the mute switch board. Fig.8 3.2.12 Removing the power switch (See Fig.9) Prior to performing the following procedure, remove the motor assembly. (1) Unsolder the two wires m on the power switch on the side of the cassette mechanism assembly. (2) Remove the screw I attaching the power switch. Fig.9 Cassette mechanism assembly Soldering l H Mute switch board Rower switch Motor assembly Soldering m I Power switch Cassette mechanism assembly (No.49869)1-13 SECTION 4 Adjustment 4.1Adjustment method ? ? Test instruments required for adjustment (1) Digital oscilloscope (100MHz) (2) Frequency counter meter (3) Electric voltmeter (4) Wow & flutter meter (5) Test tapes VT724.For DOLBY level measurement VT739.For playback frequency measurement VT712.For wow flutter & tape speed measurement VT703.For head azimuth measurement (6) Torque gauge.Cassette type for CTG-N ? ? Standard volume position Balance and Bass, Treble volume, Fader : Center (Indication 0) Loudness, Dolby NR, Sound, Cruise : Off Volume position is about 2V at speaker output with following conditions, Playback the test tape VT721. ? ? Measuring conditions (Amplifier section) Power supply voltage. DC14.4V (11V to 16V allowance) Load impedance. 4 (4 to 8 allowance) Line out level/Impedance.2.0V/20k load (250 nWb/m) AM mode999kHz/62dB, INT/400Hz, 30% modulation signal on receiving. FM mono mode97.9MHz/66dB, INT/400Hz, 22.5kHz deviation pilot off mono FM stereo mode1kHz, 67.5kHz dev. pilot 7.5kHz dev. Output level0dB (1V,50/open terminal) 1-14 (No.49869) ? ? Information for using a car audio service jig (1) Were advancing efforts to make our extension cords common for all car audio products. Please use this type of extension cord as follows. (2) As a U-shape type top cover is employed, this type of extension cord is needed to check operation of the mechanism assembly after disassembly. (3) Extension cord : EXTKSRT002-6P ( 6 pin extension cord ) For connection between mechanism assemblyand main board. (4) Check for mechanism driving section such as motor ,etc. ? ? Disassembly method (1) Remove the front panel assembly. (2) Remove the bottom cover. (3) Remove the front chassis assembly. (4) Remove the heat sink. (5) Remove the rear panel (6) Remove the main board. (7) Reattach the heat sink with the two screws D. (Refer to DISASSEMBLY.) (8) Reattach the rear panel with the screw G. (Refer to DISASSEMBLY.) (9) Reattach the front chassis assembly with the screw B. (Refer to DISASSEMBLY.) (10) Reattach the front panel assembly. (11) Confirm that current is being carried by connecting an extension cord jig. NOTE: Available to connect to the CJ701 connector when install