Yamaha-RX-777-Service-Manual电路原理图.pdf

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1、SERVICE MANUAL STEREO RECEIVER RX-777 100749 IMPORTANT NOTICE This manual has been provided for the use of authorized YAMAHA Retailers and their service personnel. It has been assumed that basic service procedures inherent to the industry, and more specifically YAMAHA Products, are already known and

2、 understood by the users, and have therefore not been restated. WARNING:Failure to follow appropriate service and safety procedures when servicing this product may result in personal injury, destruction of expensive components, and failure of the product to perform as specified. For these reasons, w

3、e advise all YAMAHA product owners that any service required should be performed by an authorized YAMAHA Retailer or the appointed service representative. IMPORTANT:The presentation or sale of this manual to any individual or firm does not constitute authorization, certification or recognition of an

4、y applicable technical capabilities, or establish a principle-agent relationship of any form. The data provided is believed to be accurate and applicable to the unit(s) indicated on the cover. The research, engineering, and service departments of YAMAHA are continually striving to improve YAMAHA pro

5、ducts. Modifications are, therefore, inevitable and specifications are subject to change without notice or obligation to retrofit. Should any discrepancy appear to exist, please contact the distributors Service Division. WARNING:Static discharges can destroy expensive components. Discharge any stati

6、c electricity your body may have accumulated by grounding yourself to the ground buss in the unit (heavy gauge black wires connect to this buss). IMPORTANT:Turn the unit OFF during disassembly and part replacement. Recheck all work before you apply power to the unit. RX-777 P.O.Box 1, Hamamatsu, Jap

7、an I CONTENTS TO SERVICE PERSONNEL . 1 IMPEDANCE SELECTOR . 1 REAR PANELS . 2 SPECIFICATIONS. 3 INTERNAL VIEW . 4 DISASSEMBLY PROCEDURES . 5 OPERATION P.C.B. CHECK. 5 AMP ADJUSTMENTS. 6 TEST MODE . 6 DISPLAY DATA . 8 IC DATA . 910 PRINTED CIRCUIT BOARD . 1122 BLOCK DIAGRAM. 2324 SCHEMATIC DIAGRAM .

8、2528 PARTS LIST . 2938 REMOTE CONTROL TRANSMITTER . 39 RX-777 RX-777 1 WALL OUTLET EQUIPMENT UNDER TEST AC LEAKAGE TESTER OR EQUIVALENT INSULATING TABLE WARNING: CHEMICAL CONTENT NOTICE! The solder used in the production of this product contains LEAD. In addition, other electrical/electronic and /or

9、 plastic (where applicable) components may also contain traces of chemicals found by the California Health and Welfare Agency (and possibly other entities) to cause cancer and/or birth defects or other reproductive harm. DO NOT PLACE SOLDER, ELECTRICAL/ELECTRONIC OR PLASTIC COMPONENTS IN YOUR MOUTH

10、FOR ANY REA- SON WHATSOEVER! Avoid prolonged, unprotected contact between solder and your skin! When soldering, do not inhale solder fumes or expose eyes to solder/flux vapor! If you come in contact with solder or components located inside the enclosure of this product, wash your hands before handli

11、ng food. I TO SERVICE PERSONNEL 1. Critical Components Information Components having special characteristics are marked Z and must be replaced with parts having specifications equal to those originally installed. 2. Leakage Current Measurement (For 120V Models Only) When service has been completed,

12、it is imperative to verify that all exposed conductive surfaces are properly insulated from supply circuits. GMeter impedance should be equivalent to 1500 ohm shunted by 0.15F. GLeakage current must not exceed 0.5mA. GBe sure to test for leakage with the AC plug in both polarities. I IMPEDANCE SELEC

13、TOR IMPEDANCE SELECTOR WARNING: Do not change the IMPEDANCE SELECTOR switch setting while the power to this unit is on, otherwise this unit may be damaged. RX-777 RX-777 2 I REAR PANELS U model C model A model RX-777 RX-777 3 I SPECIFICATIONS I AUDIO SECTION Minimum RMS Output Power (Power Amp. Sect

14、ion) 8 ohms, 20 Hz to 20 kHz, 0.019% THD .100W + 100W 6 ohms, 20 Hz to 20 kHz, 0.03% THD .120W + 120W Dynamic Power Per Channel (IHF) 8/6/4/2 ohms . 140/170/220/290 W Power Band Width 8 ohms, 50W, 0.03% THD .10 Hz to 50 kHz Damping Factor 8 ohms, 20 Hz to 20 kHz, SPEAKER-A . 240 or more Input Sensit

15、ivity / Input Impedance PHONO MM . 2.5 mV / 47 k-ohms CD, etc. . 150 mV / 47 k-ohms MAIN IN . 1 V / 30 k-ohms Maximum Input Signal Level PHONO MM (1 kHz, 0.015% THD) . 115 mV CD, etc. (1 kHz, 0.015% THD) . 2.2 V Output Level / Output Impedance PRE OUT . 1 V / 1.2 k-ohms REC OUT (PHONO) . 150 mV / 1.

16、7 k-ohms Headphone Jack Rated Output / Impedance 0.015% THD, 8 ohms, 1 kHz, 150 mV . 0.47 V / 470 ohms Frequency Response CD, etc. (20 Hz to 20 kHz). 00.5 dB MAIN IN (20 Hz to 20 kHz) . 00.5 dB CD (CD DIRECT AMP ON, 20 Hz to 100 kHz) . 01.0 dB RIAA Equalization Deviation PHONO MM (20 Hz to 20 kHz) .

17、 0 0.5 dB Total Harmonic Distortion (20 Hz to 20 kHz) PHONO MM, to REC OUT (3 V) .0.008% or less CD, etc. to PRE OUT (1 V) .0.007% or less CD, etc. to SP OUT (50 W / 8 ohms) .0.012% or less Signal to Noise Ratio (IHF-A network) PHONO MM (5 mV Input shorted) .87 dB or more CD (CD DIRECT AMP ON, 150 m

18、V Input shorted) .110 dB or more Residual Noise (IHF-A network) CD DIRECT AMP ON . 30 V PURE DIRECT ON . 110 V Channel Separation CD, etc. (Input 5.1 k-ohms shorted, 1 kHz).65 dB or more CD, etc. (Input 5.1 k-ohms shorted, 10 kHz).50 dB or more Tone Control Characteristics Bass:Boost/Cut . 10 dB (20

19、 Hz) Turnover Frequency . 350 Hz Treble: Boost/Cut . 10 dB (20 kHz) Turnover Frequency . 3.5 kHz Continuous Loudness Control Attenuation, 1 kHz. -30 dB Gain Tracking Error 0 to -60 dB. 2 dB or less I FM Section Tuning Range U, C models . 87.5 to 107.9 MHz A model .87.50 to 108.00 MHz 50 dB Quieting

20、Sensitivity (IHF) (1 kHz, 100% Mod.) Mono . 2.0 V (17.3 dBf) Stereo . 25 V (39.2 dBf) Usable Sensitivity (IHF) Mono . 1.0 V (11.2 dBf) Selectivity at 400 kHz . 70 dB Signal to Noise Ratio (IHF) Mono / Stereo .76 dB / 70 dB Harmonic Distortion (1 kHz) Mono / Stereo . 0.2 / 0.3 % Stereo Separation 1 k

21、Hz . 45 dB Frequency Response 20 Hz to 15 kHz .+0.5 / -2 dB Antenna Input . 75 ohms unbalanced I AM Section Tuning Range U, C models . 530 to 1,710 kHz A model . 531 to 1,611 kHz Usable Sensitivity . 300 V/m Antenna . Loop Antenna I Video Section Video Signal Type U, C models . NTSC A model . PAL Vi

22、deo Signal Level . 1 Vp-p / 75 ohms Maximum Input Level . 1.5 Vp-p Signal to Noise Ratio .50 dB or more Monitor Out Frequency Response .5 Hz to 10 MHz, -3 dB I General Power Supply U, C models .AC 120 V, 60 Hz A model .AC 240 V, 50 Hz Power Consumption U model . 260 W C model . 210 W A model . 200 W

23、 Standby Power Consumption U, C models . 0.9 W A model . 1.0 W AC Outlets U, C models 2 switched outlets . 100W max. total A model 1 switched outlet . 100W max. Dimensions (W x H x D) . 435 x 151 x 390.3 mm (17-1/8 x 5-15/16 x 15-5/16) Weight . 9.8 kg (21 lbs. 10 oz.) Finish . Black color Accessorie

24、s . Remote control transmitter x 1, Manganese batteries (size AA, R06) x 2, Indoor FM antenna x 1, AM loop antenna x 1 * Specifications are subject to change without notice. U . U.S.A. modelC . Canadian model A . Australian model RX-777 RX-777 435 (17-1/8) Unit : mm (inch) 151 (5-15/16) 130 (5-1/8)3

25、48 (13-11/16) 21 (13/16) 21 (13/16) 21.3 (13/16) 390.3 (15-5/16) DIMENSIONS 4 I INTERNAL VIEW wrtyuei o !1 !2!0!3!4!5!6 q q MAIN (5) P.C.B. w MAIN (2) P.C.B. e MAIN (3) P.C.B. r MAIN (1) P.C.B. t INPUT (4) P.C.B. y INPUT (1) P.C.B. u INPUT (2) P.C.B. i INPUT (3) P.C.B. o OPERATION (8) P.C.B. !0 OPER

26、ATION (1) P.C.B. !1 OPERATION (6) P.C.B. !2 MAIN (4) P.C.B. !3 OPERATION (4) P.C.B. !4 OPERATION (5) P.C.B. !5 OPERATION (2) P.C.B. !6 OPERATION (3) P.C.B. RX-777 RX-777 Top Cover Bottom Cover Front Panel q r e r r e w q Fig. 1 Rear Panel OPERATION (8) P.C.B. Cable Solder the end of the wire to the

27、ground point of OPERATION (8) P.C.B. (refer to P.15 D-4) J420 J421 Operation P.C.B. (8) Rear Panel q q q w w 5 I OPERATION P.C.B. CHECK Preparation before OPERATION P.C.B. Check a. Remove the Top Cover. b. Remove 13 screws (q) on the Rear Panel as shown in Fig. 1. c. Remove 2 screws (w) on the OPERA

28、TION (8) P.C.B. as shown in Fig. 1. Fig. 1 Fig. 2 d.Spread a cloth over the Main Chassis as shown in Fig. 2. e.Put the OPERATION (8) P.C.B. on end as shown in Fig. 2. f. Connect the ground point of OPERATION (8) P.C.B. to rear panel by using wire as shown in Fig. 2. f. Connect the ground point of OP

29、ERATION (8) P.C.B. to rear panel by using wire as shown in Fig. 2. g. Connect the J420, J421 of OPERATION (8) P.C.B. to rear panel by using wire as shown in Fig. 2. CAUTION! The ground point, J420 and J421 must be connected to Rear Panel to keep the circuit in normal operation when OPERATION (8) P.C

30、.B. is removed from main chassis. I DISASSEMBLY PROCEDURES (Remove parts in the order as numbered.) Disconnect the power cord from the AC outlet. 1. Removal of Top Cover Remove 4 screws (q) and 4 screws (w) in Fig. 1. 2. Removal of Front Panel Remove 7 knobs and 6 screws (e) in Fig. 1. 3. Removal of

31、 Bottom Cover Remove 6 screws (r) in Fig. 1. RX-777 RX-777 6 I AMP ADJUSTMENTS Confirmation of Idling Current Right after power is turned on, confirm that the voltages of between R111-R135 and R112-R136 are between 0.1mV and 10mV. If they exceed 10mV, cut R175, R176. Then reconfirm they are between

32、0.1mV and 10mV. Note) If R175 (L ch) or R176 (R ch) have already been cut off and idling current does not flow, reconnect R175 (1k) or R176 (1k). Q117 and Q118 are transistors for temperature correction. Apply silicone grease to the contact surface with the heat sink. R111 R175R176 R135 L ch 0.1mV 1

33、0.0mV (DC) R112 R136 R ch 0.1mV 10.0mV (DC) R175 (L ch) R176 (R ch) Cut off I TEST MODE CAUTION: Before setting to the TEST mode, write down the existing preset memory content of the Tuner in a table as shown below. (This is because setting to the TEST mode will cause the memory content to be as fac

34、tory set, i.e., all the preset memory by the user will be erased.) Preset groupP1P2P3P4P5P6P7P8 A B C D E Preset groupP1P2P3P4P5P6P7P8 A/C/EU, C87.5 MHz90.1 MHz95.1 MHz98.1 MHz107.9 MHz88.1 MHz106.1 MHz 107.9 MHz A87.5 MHz90.1 MHz95.1 MHz98.1 MHz108.0 MHz88.1 MHz106.1 MHz 108.0 MHz B/DU, C630 KHz108

35、0 KHz1440 KHz530 KHz1710 KHz900 KHz1350 KHz1400 KHz A630 KHz1080 KHz1440 KHz531 KHz1611 KHz900 KHz1350 KHz1404 KHz G Factory preset memory content RX-777 RX-777 1. Test mode for the DISPLAY to light all segments. Turn the POWER SW ON while pressing the EDIT and No. 8 keys simultaneously. The unit enters the TEST mode for the DISPLAY to light all segments. 2. Test mode for the microprocessor software version check. While in the DISPLAY test mode, push the No. 1 key to enter the TEST mode for the microprocessor software version check. 3. Memory reset mode While