JVC RC-770 L, RC-770LB, RC-770LD, RC-770LS SERVICE MANUAL

Page 1

No. 1531 June 1983

Page 2

	Page
Specifications	. 2
Safety Precautions	3
Locations of Controls	3
Locations of Main Parts	. 4
How to Engage Dial Cord	4
Removal of the Main Parts	5
Adjustment of Cassette Mechanism	7
Tuner Alignment	. 8
Adjustment of Cassette Recorder Amplifier	11
Block Diagram	. 11
Standard Schematic Diagram of RC-770L/LB ((Tuner Circuit)	12
Standard Schematic Diagram of RC-770LD/LS (Tuner Circuit)	. 13
Standard Schematic Diagram of RC-770L/LB (Amplifier Circuit)	. 14
Standard Schematic Diagram of RC-770LD/LS (Amplifier Circuit)	. 15
Wiring Connection	. 16
Amplifier P.W. Board Parts and Parts List	. 17
Amplifier P.W. Board Parts List	. 17
Other P.W. Board Parts List	. 18
Tuner P.W. Board Parts and Parts List	. 19
Tuner P.W. Board Parts List (RC-770L/LB)	. 19
Enclosure Assembly and Electrical Parts List	. 20
Enclosure Assembly and Electrical Parts	. 21
Mechanism Component Parts	. 22
Mechanism Component Parts List	. 23
Packing	. 25
Packing Material Parts List	. 25
AccessoriesBack C	over

Specifications

Speakers	: 12 cm (3.2 Ω)×2, 2 cm×2	Amplifier section
Tuner section		Power output	: Max. 6 W (3 W + 3 W) at 3.2 Ω
Frequency ranges	: FM 88–108 MHz		2.2 W per channel at 10% THD
	MW 540-1600 kHz	Input jacks	: Mic×2 (1 mV,−60 dBV,
	LW 150-350 kHz		200~2 kΩ)
	SW 6-18 MHz	Output jacks	: Headphone × 1
Antennas	: Telescopic antenna for FM & SW	Power supply	: DC 9 V (6 ''R20'' batteries)
	Ferrite core antenna for MW & LW		Car battery (DC 9 V)
Tape recorder sect	ion		AC 240/220/110 V, 50/60 Hz
Track system : 4-Track 2-Channel stereo		Power consumption : 10 W (RC-770LB), 9 W (RC-
Frequency respons	e: 80–12,000 Hz		770L/LD)
Wow & flutter	: 0.19% (WRMS)	Dimensions	: 520(W)×239(H)×136( D) mm
S/N ratio	: 54 dB (Normal tape)		(20-1/2″×9-1/2″×5-3/ 8 ″)
Rewind time	: Approx. 120 sec. (C-60 cassette)	Weight	: Approx. 3.2 kg (7.0 lbs)
Fast forward time	: Approx. 120 sec. (C-60 cassette)		(without batteries)
Head	: Permalloy Head for Playback/
	Recording 2-Gap permalloy Head	Design and specific	ations subject to change wit hout notice.
	for erasure
Motor	: Electronic DC motor ×1

Page 3

Safety Precautions

▲ Safety mark

Safety is very important with this unit. When replacing the parts marked A , be sure to use only those designated parts. The designated resistors, diodes, transistors become hot in use. When replacing, be sure to secure them with a distance of more than 5 mm from the circuit board. In addition, they are banded together to avoid touching other wiring, recheck this point as well after repair.

The wiring of the primary side should be wound more than one and half times, then soldered.

Fig. 2

Locations of Controls

Page 4

Locations of Main Parts

How to Engage Dial Cord

1. Turn the dial drum fully counterclockwise (to the lowest frequency).
2. Use Kevlar cord (1000 mm long and 0.5 mm in diameter).
3. Install the string in the sequence of the numbers.

1. Rec Safety Lever
2. Supply Reel Assembly
3. Take-up Reel Assembly
4. Counter belt
5. DC motor
6. O Rec Button
7. Erase Head
8. Rec/P.B. Head
9. Pinch roller Arm Assembly
10. Tape Counter

Fia. 4

Fig. 5

1. Handle Assembly

2. Ferrite core antenna
3. Band Switch
4. Tuner P.W. Board Assembly
5. Variable Capacitor
6. Amplifier P.W. Board Assembly
7. Tweeter speaker
8. Power supply P.W. Board Assembly
9. Woofer Speaker
10. Tuning shaft
11. Control P.W. Board Assembly
12. Woofer speaker

Page 5

Removal of the Main Parts

Rear Cabinet and Telescopic Antenna (Fig. 8)

1) Remove the Battery cover
2) Remove 7 screws (1) fastening the Rear cabinet.
3) To remove the Telescopic antenna only, remove a screw (2) fastening the T. antenna (need not the rear cabinet)

Tuner P.W. Board (Fig. 9)

Remove 5 screws 3 fastening the Tuner P.W. Board.
2) Remove the parallel wire from the tuner P.W. Board.

When removing the parallel wire, it's convenient for connecting then again to do marking both on the wire side and socket side.

Amp P.W. Board (Fig. 9)

1) Remove 4 screws (4) fastening the Amp P.W. Board
2) Remove the parallel wire on the control P.W. Board.
3) Remove 3 connectors.
4) Cutting the wire band

Power supply P.W. Board (Fig. 9)

Remove 3 screws (5)

Control P.W. Board (Fig. 9)

1) Remove 3 Volume knobs
2) Remove 3 nuts (6) fastening the control volume

Mechanism assembly (Fig. 10)

1) Remove 5 screws 7 fastening the mechanism ass'y.
2) Open the cassette door.
3) Remove the erase head wire bonded from clamp

Speaker (Fig. 10)

Remove 8 screws (8) and (9) fastening the speaker of Lch and Rch.

LED P.W. Board (Fig. 11)

1) Release the hook to open the P.W. Board.
The hook should be cut and bonded in place after replacing the LED.

Page 6

Mechanism Parts

Fig. 12

1) REC/PB head Remove a screw (
Remove a screw (6) for adjustment. 2) Erase head
Bemove a screw ( Remove a screw (8
3) Pinch roller assembly

Remove an E-ring (9) holding its assembly. Pull it off from the shaft.

4) Supply reel disc

Pull out the reel disc stopper (10) and pull out its disc from shaft

If you broke the stopper, you can use E-ring (REE-1200) in place of stopper.

Fia. 13

5) Take-up reel disc Remove the counter belt (11). (Be careful not to stain the counter belt.) Pull out the reel disc stopper (12) and pull out its disc from shaft. 6) Motor Remove the main belt (13). (Be careful not to stain the main belt.)

Remove 3 screws (14) fastening the motor.
7) Flywheel
- 1. Remove the main belt (13).
- 2. Remove a washer (15) fastening the capstan shaft
- 3. Pull off the flywheel.
- Note: When replacing the flywheel, be sure to emplov washers and spring

Page 7

Adjustment of Cassette Mechanism

Check the following items after cassette mechanism parts are replaced.

	ltem	Requirements	Test equipment	Test tape
1.	Source voltage	Rated voltage: 9.0 V DC Motor operating voltage range: 5.0–11 V DC	Regulated power supply
2.	Tape speed	4.8 cm/sec (3,000 Hz) – 2% Deviation + 3%	Frequency counter (digital counter)	VTT-656A
3.	Wow & flutter	Less than 0.35% (RMS)	Wow meter	VTT-656A
4.	Take-up torque	PLAY 35-75 g.cm FF 60-200 g.cm REW 60-200 g.cm	During FF and rewind, the idlers, reels and flywheel should not slip against each other when the reels are locked.
5.	Current consumption (of motor alone)	PLAY150 mA or lessFF250 mA or lessREW250 mA or less	DC ammeter	C-60 (take-up torque should be normal when tape is used.)
6.	Pinch roller pressure	375~475 g	Tension gauge Pull the pinch roller perpendicularly and read the gauge when the pinch roller just stops.
7.	Head position during PLAY and RECORD	E Cassette Guide	During PLAY (RECORD) the dimensional requirements given here must be met, and the heads must not contact the cassette case.	Any cassette tape
8.	Auto-stop operation and extent move- ment	40~70 g Within 3.5~55mm	Tension gauge Pull the Auto stop lever perpendicularly and read the gauge when the mechanism just Auto matically stops.	Any cassette tape

Page 8

Tuner Alignment

BASIC CONDITIONS

POWER SOURCE OF THE RECEIVER	DC 9 V, AC240/220/110 V, 50/60 Hz.
LOAD RESISTANCE OF THE RECEIVER	50 mW (0.4 V)/3.2 Ω
MODULATION OF SSG	400 Hz. 30%
Item	Description
1. AM IF ALIGNMENT 1-1 Conditions of the receiver. (1) Power source: (2) Function switch position: (3) Band select switch: (4) Volume control: (5) Tone control: (6) Variable capacitor: 1-2 Connection of Sweeper and the receiver (1) Tuner input: (2) Tuner output: 1-3 Aligning position: 1-4 Alignment (Waveform):	DC 9 V (When the power is supplied directly to the tuner in the receiver, the voltage should be adjusted to the proper level which shall be required by the tuner.) RADIO MW Minimum gain position Center (Bass, Treble) position Near the minimum capacity position where no signal come in. Positive side to TP4 Positive side to TP5 Negative side to TP6 CFT, T3 Adjust AM I.F.T. (above mentioned aligning position) so that maximum and symmetrical wave form can be obtained. In this case, the wavehead should be appeared at the center marker (450 kHz) on the scope of Sweeper.
2. FM IF ALIGNMENT 2-1 Conditions of the receiver (1) Power source: (2) Function switch position: (3) Band select switch: (4) Volume control: (5) Tone control: (6) Variable capacitor: 2-2 Connection of Sweeper and the receiver (1) Tuner input: (2) Tuner output:	Same as mentioned in item 1-1 RADIO FM Minimum gain position Center (Bass, Treble) position Near the minimum capacity position where no signal corne in. Positive side to TP3 Positive side to TP5 Negative side to TP6
NOTE a) Attach a capacitor (30 pF) and a resistor (3 Sweeper input. b) Attach a resistor (100 kΩ) in series to the p	0 kΩ) to the positive side cable which shall be led from ositive side cable which shall be led from Sweeper output.
2-3 Aligning position: 2-4 Alignment (Waveform):	a) IF Waveform: T1 b) -Discriminate Waveform: T2 (''S'' curve waveform) Adjust the discriminate coil (T2) so that ''S'' curve waveform may be changed to IF waveform as shown in followin € f igure.
Ь) Discriminate Waveform:	After above, adjust T1 so that max. sensitivity and syn- metrical IF waveform can be obtained on the scope of Sweeper. Adjust the discriminate T2 again so that above symmer ical IF

Page 9

	Item		Description
3. AM RF ALIGNMENT 3-1 Conditions of the receiver. (1) Power source: (2) Function switch position: (3) Volume control: (4) Tone control: (5) Variable capacitor: 3-2 Conditions of SSG. (1) Modulation: (2) Frequency: (3) Output level of the attenuator in SSG: 3-3 Power output measuring position: 3-4 Alignment:		Same as mentioned in item 1-1. Radio 50 mW Center (Bass, Treble) position Refer the following list shown in item 3-4. Refer the basic condition Refer the following list shown in item 3-4. Approx. 50 mW Speaker terminals
	Band Select Switch Position	Sort of Antenna to be attached to SSG	Frequency of SSG	Variable Capacitor Position	Aligning Position
1			520 kHz	Max. capacity	L7
2	1		1,650 kHz	Min. capacity	TC-8
3	MW	Loop Antenna	tenna Ajust the above aligning position (L7 & TC-8) repeatedly so that the tuner can be received above frequency range (band width).
4			620 kHz	to be received 620 kHz	L4
5			1,400 kHz	to be received 1,400 kHz	TC-6
6	-		Adjust the above align that the tuner can be	ning position (L4 & TC-6) repea obtained the best sensitivity.	itedly so
7			145 MHz	Max. capacity	L6
8	_		360 MHz	Min. capacity	TC-7
9	LW	Loop Antenna	Adjust the above alig that the tuner can be width)	ning position (L6 & TC-7) repeating position (L6 & TC-7) repeating received above frequency rang	itedly so e (band
10			160 MHz	to be received 160 MHz	L3
11			350 MHz	to be received 350 MHz	TC-5
12			Adjust the above aligning position (L3 & TC-5) repeatedly so that the tuner can be obtained the best sensitivity.
13			5.8 MHz	Max. capacity	L8
14	1		18.6 MHz	Min. capacity	TC-4
15	sw	Dummy Antenna	Adjust the above align that the tuner can be width).	ning position (L8 & TC-4) repeat received above frequency rang	tedly so e (band
16			6.0 MHz	to be received 6.0 MHz	L5
17			18.0 MHz	to be received 18.0 MHz	TC-3
18			Adjust the above aligr that the tuner can be	ning position (L5 & TC-3) repea obtained the best sensitivity.	tedly so

Page 10

	lte	em		Description
4. FI	M RF ALIGNMENT	•
4-1	Conditions of the	receiver.
(1)	Power source:		Same as mentione	Same as mentioned in item 1-1.
(2)	Function switch p	position:	Radio
(3)	Band select swite	sh:	FM
(4)	Volume control:		50 mW
(5)	Tone control:		Center (Bass, Treb	le) position
(6)	(6) Variable capacitor:		Refer the following	g list shown in item 4-3.
4-2	Condition of FM	SSG.
(1)	(1) Modulation:		Refer the basic cor	ndition
(2)	Frequency:		Refer the following	j list shown in item 4-3.
(3)	Output level of th	e attenuator in FM
SSG: The level shall be decided by the load resistance of the receiver			of the receiver
			mentioned in the b	asic conditions.
4-3	Alignment:
	Band Select Switch Position	Sort of Antenna to be attached to SSG	Frequency of SSG	Variable Capacitor Position	Aligning Position
1			87.5 MHz	Max. capacity	L2
2			109.0 MHz	Min. capacity	TC-2
3	FM	Dummy Antenna	Ajust the above aligni the tuner can be recei	ng position (L2 & TC-2) repeat ved above frequency range (ba	edly so that ind width).
4			90 MHz	to be received 90 MHz	L1
5			108 MHz	to be received 108 MHz	TC-1
6			Adjust the above aligr that the tuner can be	ning position (L1 & TC-1) repeat obtained the best sensitivity.	itedly so

FM MPX Alignment

19 kHz Alignment (Regular Method)
1. Connect a frequency counter to the test point TP7 (earth = TP6).
Supply the monaural signal (98 MHz, 60 dB) across the test points TP1 and TP2.

Parts Arrangement for Alignment

3. Adjust the variable resistor VR1 so that the frequency becomes 19 kHz ± 100 Hz.

Dummy Antenna

R1 + R2 = 80 Ω C = 10 pF R1: Output impedance of S.S. G.

Page 11

Adjustment of Cassette Recorder Amplifier

Fig.	15

	Model RC-770 L/LB/LD/LS			Cassette section
	Source voltage	DC : 9 V,	Load	0 dBS (0.775 V)/3.2Ω
		AC : 240/220/110 V	Input	MIC. – 58 dBS TUNER – 29 dBS
Step	Item	Adjus	tment method
1	Speed and wow/flutter	When measured by wow/flutter m equivalent, wow/flutter should be curacy should be within +15 Hz,	neter with test within 0.35% I – 15 Hz at 30	tape VTT-656 (3000 Hz) or its RMS. At this time, tape speed ac- 20 Hz.
2	Azimuth	Play back test tape VTT-658, then ed.	Play back test tape VTT-658, then adjust azimuth so that output at TP-1 is maximized.
3	PB level	Playback test tape VTT-664, then adjust VR101 and VR201 so that outputs at TP-1 and TP-2 become -21±0.5 dBs.
4	PB frequency response (checking)	Use test tape VTT675N or the equipment of the sequence of the should be as follows at 0 dB and 1	Use test tape VTT675N or the equivalent. The values should be as follows at 0 dB and 1000 Hz.
		250Hz 10kHz 12.5kHz 3dB 4dB
5	Frequency of bias current	Cut off the TUNER input and put the unit into REC mode with BEAT CUT switch at ''1'', then adjust L301 so that frequency of bias current at TP-4 becomes 67.5 kHz ± 0.1 kHz.
6	Magnitude of bias current	Cut off the TUNER input, then adju currents become 420 μA (voltages 10 Ω are 4.2 mV).	st VR301 and at TP-4 across	VR302 so that Rch and Lch head R128 10 Ω at TP-5 across R228
7	REC/PB level	Apply input at – 38 dBs from TUN and PB levels at TP-1 and TP-2 are	ER, then adjust equal (within	t VR102 and VR202 so that REC ± 1 dB).
8	REC/PB frequency response (checking)	Record the following specified sign recording. Then, the respective dev should be within the following rang Normal tape :	nals at input lev viations in outp ges.	vel of – 20 dB and play back the but level from 1000 Hz reference
9	Dolby effect	Put the unit into PLAY mode withor check that output difference betwee and OFF with the following filter is	out cassette, th een Dolby ON 9 dB ±2 dB.

Block Diagram

Tuner Signal Diagram

Recording System

Play Back System

Signal Diagram

(No. 1531) 11

Page 12

Fig. 19

Page 13

Fig. 20

Page 14

Page 15

RC-770 L/LB/LD/LS

Page 16

RC-770 L/LB/LD/LS

(No. 1531) 16

Page 17

Amplifier P.W. Board Parts and Parts List

Dolby ON/OFF

Level Adjust (P)

3 kΩ

Beat Cut

CN101

QMV5004-006

QMV5005-002

QMV5004-002

Connector

J102

QMS6312-012 Head Phone Jack

M51544L

BA1102F

PRE. Amp

Dolby Amp

S103

S104

VR101,201

QSS1201-026

QSS1301-101G

QVP8A0B-033 V. Resistor

2SC536(H)

2SC1684(R,S)

Q301

Q402

Page 18

▲ parts are safety assurance parts. When replacing those parts, make sure to use the specified one.

Other P.W. Board Parts List

		(	1
Ref. No.	Parts No.	Parts Name	Remarks	Q′ty
Q401 D101,201	2SC1317(R,S) MA165	″ Si. Diode		1 2
D102,202 D401,402 L101,201	″ HZ6C3 VQP0001-473S	^" Zener Diode Inductor		2 2 2
L102,202 L103,203	VQP0001-472S VQP0001-562SV	"		2 2
L301 C101,201 C102,202	VQH1009-026 QET41HR-104 QCY41HK-122	OSC Coil E. Capacitor C. Capacitor	1 μF 50 V 0.0012 μF	2 2 2″
C103,203	QET41HR-475	E. Capacitor	4.7 μF ″ 100 μF 10 V	2
C104,204 C105,205 C106,206 C107,207	QET41AR-107 QET41ER-226 ″-106 QCY41HK-102	″ ″ C. Capacitor	22 μF 25 V 10 μF ″ 0.001μF 50 V	2 2 2 2
C108,208 C109	QFV41HJ-683 QET41AR-476	T.F. Capacitor E. Capacitor	0.068μF ″ 47 μF 10 V	2 1
C110 C111 C112 212	QET41ER-226 QET41AR-227 QCX41HK-682	″ ″	22 μF 25 V 220 μF 10 V 0.0068μE 50 V	1 1 2
C113,213 C114,214 C115,215	QET41ER-106 QFN41HJ-472 QET41ER-475	E. Capacitor M. Capacitor E. Capacitor	10 μF 25 V 0.0047μF 50 V 4.7 μF 25 V	2 2 2
C116,216 C117,217	QFV41HP-333 QCC11EM-103	T.F. Capacitor C. Capacitor	0.033μF 50 V 0.01μF 25 V	2 2
C118,218 C119,219 C120,220	QET41ER-475 QET41HR-104 QEB41HM-334	E, Capacitor	4.7 μF ″ 0.1 μF 50 V 0.33 μF ″	2 2
C120,220 C121,221 C122	QCY41HK-102 QET41ER-226	C. Capacitor E. Capacitor	0.001 μF ″ 22 μF 25 V	2 1
C123,223 C124,224 C125,225 C126,226	QET41ER-106 QCC11EM-154 QET41AR-336 QET41AR-477	" C. Capacitor E. Capacitor "	10 μF ″ 0.15 μF ″ 33 μF 10 V 470 μF ″	2 2 2 2
C127,227 C128	QET41HR-335 QET41ER-106	"	3.3 μF 50 V 10 μF 25 V	2
C129,229 C130,230 C131,231 C132,232	QET41HR-105 QFV41HJ-333 QET41HR-105 QCS11HJ-121	" T.F. Capacitor E. Capacitor C. Capacitor	1 μF 50 V 0.033μF ″ 1 μF ″ 120 pF ″	2 2 2 2
C134,234 C135,235 C136,237 C138,238 C129,239	QET41HR-335 QCY21HK-471 QCS11HJ-151 QCY11HK-102	E. Capacitor C. Capacitor " "	3.3 μF " 470 pF 50 V 150 pF " 0.001 μF " 100 pF "	2 2 2 2 2
C140,240 C141,241 C301 C302	QCC11EM-223 QCS11HJ-101 QCY41HK-272 QCC11EM-223	"	0.022μF 25 V 100 pF 50 V 0.0027μF ″ 0.022μF 25 V	2 2 1 1
C304 C305	QFN41HJ-273 QCY41HK-682	M. Capacitor C. Capacitor	0.027μF 50 V 0.0068μF ″
C306 C307,308 C401 C402	QCY41HJ-682 QCS11HJ-301 QET41CR-228 QET41AR-108	E. Capacitor	300 pF ″ 2200 μF 16 V 1000 μF 10 V	1 2 1 1
C403 C404	″ -476 ″ -107	""	47 μF ″ 100 μF ″	1
C406 C407 C408	// -477 // -337 // -107	""	470 μF ″ 330 μF ″ 100 μF ″	1 1 1
C409 C410 C411	" -107 " -337 " -227	" "	″″″″ 330 μF″ 220 μF″	1
R403	QRD161J-xxx QRD141J-100	Carbon Resistor Fusible Resistor	- 1/6 W 1 Ω 1/4 W	69 1

Ref. No.	Parts No.	Parts Name	Remarks	Q′ty
	8-001B> P.W. Board (fo	r ST. IND)
D3	LN224RP	LED		1
	trol Ass′y>
VMW1	064-00XB P.W. Board
VR501,601	QVN5A2A-054M	V. Resistor	Treble 50 kΩ	2
VR502,602	QVN5A2D-024M	"	Bass 20 kΩ	2
VR503,603	QVN5A2A-054M	"	Volume 50 kΩ	2
Q501,601	2SC1684(R,S)	Transistor		2
C501,601	QET41HR-105	E. Capacitor	1 μF 50 V	2
C502,602	″ -105	"	" "	2
C503,603	QCY41HK-682	C. Capacitor	0.0068µF″	2
C504,604	QCC11EM-333	"	0.033µF 25 V	2
C505,605	QCY41HK-222	"	0.0022 μ 50 V	2
C506,606	QET41HR-154	"	Ο.15 μF ″	2
R501,601	QRD161J-224	C. Resistor	220 kΩ 1/6 W	2
R502,602	″ -222	"	2.2 kΩ ″	2
R503,603	″ -221	"	220 Ω ″	2
R504,604	″ -103	"	10 kΩ ″	2
R505,605	″ -222	"	2.2 kΩ ″	2
R506,606	″ -472	"	4.7 kΩ ″	2
	pply Ass'y>
VMW1064	-OOXC P.W. Board	C. Divite
D701,702	TUE2			2
0703,704	0051140 222	C. Conneitor		2
C707,702	200F11HP-223			2
0705	-223 11F2	Si Diode
0700
J701	- QMC0263-002	AC. Socket
1700		DC leak	LB
5702	QIVIAU921-005
3701	- USSZ3Z5-10785 // 107			\| ' \|
	107 \/NID4003-037	Fuse Label
	VYH5422-001	Barrier	IB
	1110422 001	Samo

DIN P. W. Board (RC-770LD/LS)

Amp. P.W. Board (RC-770LD/LS)

Fig. 25

+B Earth

DIN P. W. Board (RC-770LD/LS)

Ref. No.	Parts No.	Parts Name	Remarks	Qʻty
J801	QMC9014-006	DIN Jack Ass'y		1
Q801,901	2SC1843 (F)	Transistor		4
802,902
D801,901	MA165	Si. Diode		4
802,902
R802,902	QRD144J-103S	C. Resistor	10 kΩ 1/4 W	2
R803,903	″ -181S	"	180 Ω ″	2
R804,904	″ -332S	"	3.3 kΩ ″	2
R805,905	″ -155S	"	1.5 MΩ ″	2
R806,906	″ -151S	"	150 Ω ″	2
R807,907	″ -332S	"	3.3 kΩ ″	2
R808,908	″ -225S	"	2.2 MΩ ″	2
R809,909	″ -472S	"	4.7 kΩ ″	2
R810,910	″ -224S	"	220 kΩ ″	2
R451	″ -222S	"	2.2 kΩ ″	1
C801 ~ 804	QET41HR-105	E. Capacitor	1 μF 50 V	8
901 ~ 904
C805,905	QCS11HJ-471	C. Capacitor	470 pF ″	2
C451	QET41AR-476	E. Capacitor	47 μF 10 V	1
C452	″ -107	"	100 μF ″	1
CN801	QMV5004-007	Connector		1

Amp. P.W. Board Parts List (RC-770LD/LS)


Ref. No.	Parts No.	Parts Name	Remarks	Q'ty
S105	QST3101-V04	Push Switch	RADO/DIN	1
C116,216	QFV41HJ-333	T.F. Capacitor	0.0 3 µ F 50 V	2
C117,217	″ -103	"	0.01 µF ″	2
C118,218	QET41HR-475	E. Capacitor	4.7 L F "	2
C119,219	QFV41HJ-104	T.F. Capacitor	0.1 µ F ″	2
C120,220	″ -333	"	0.03 3 µF ″	2
C126,226	QETC1AM-477	"	″ F بر470	2
C139,239	QCS11HJ-101	"	100pF "	2
C304	QFV41HJ-273	"	0.02 7 µF ″	\| 1
C306	QCY41HK-821	C. Capacitor	820pF ″	1
C310	QET41CR-477	E. Capacitor	470µF 16 V	1
C406	QETC1AM-477	"	″ 10 V	1
C407	″ -337	"	" F آير330	1
C411	QET41AR-337	"	" "	1
R	QRD161J-xxx	C. Resistor	1/6 W	66
R409	QRD121J-1R0	"	1 Ω 1/2 W	1

Page 19

Tuner P.W. Board Only Parts List (RC-770LD/LS)

Ref. No.	Parts No.	Parts Name	Remarks	Q′ty	Ref. No.	Parts No.	Parts Name	Remarks	Qʻty
L1 L2 IC1 R1 R2	VQF1B12-001 V03105-029 TA7358A QRD161J-101 ″ -271	RF Coil OSC Coil IC C. Resistor	(FM) ″ 100 Ω 1/6 W 270 Ω ″	1 1 1 1	C9 ″ C14	QCT05CH-220 QCT05CH-150 QCS11HJ-200 " -470	C. Capacitor	22 pF 50 V (LD) 15 pF ″ (LS) 20 pF ″ (LD) 47 pF ″ (LS)	1 1 1 1
R3 R4 R16 ^" R36 C1	"-393 "-334 "-561 "-102 "-220 QCS11HJ-180	" " C. Capacitor	39 kΩ ″ 330 kΩ ″ 560 Ω ″ (LD) 1 kΩ ″ (LS) 22 Ω ″ 18 pF 50 V	1 1 1 1 1	C17 ~ C39 C62,63 C64 ~	"-100 "-8R0 QCC11EM-473 QCF11HP-103 QCT05CH-2R0 "-3R0	"" "	10 pF " (LD) 8 pF " (LS) 0.047 μF 25 V 0.01 μF 50 V 2 pF " (LD) 3 pF " (LD)	1 1 1 1 1 1
C2 C3 C4 C5 C6 ″	"-150 "-220 QCY11HK-472 QCT05CH-100 "-200 "-180	""""""""""""""""""""""""""""""""""""""	15 pF " 22 pF " 0.0047μF " 10 pF " 20 pF " (LD) 18 pF " (LS)	1 1 1 1 1	D1 D2 D4	MA165 1S553T MA165	Diode Variable Capacitor Diode	(LD)	1

Tuner P.W. Board Parts List (RC-770L/LB)

A parts are safety assurance parts. When replacing those parts, make sure to use the specified one.

Ref. No.	Parts No.	Parts Name	Remarks	Q′ty	Ref. No.	Parts No.	Parts Name	Qʻty
VC-1~4 TC-1~4	QAP1224-520V	V. Capacitor		4	L3,4	VQB012B-314	Ferrite Core Antenna Ass'y	2
TC5,6,7,8	QAT2002-001	T. Capacitor		4	T1	VQT7F12-104	IFT	1
VC5	QAT5001-004	M.V. Capacitor		1	T2	″ -104	"	1
VR1	QVZ3512-103	V. Resistor		1	ТЗ	VQT7A11-203	IFT	1
L1	VQF1B12-007	RF Coil	FM	1	CF1,2	VCF2L3B-301	C. Filter	2
L2	VQB1B10-001	OSC Coil	"	1	CFT	VQT7A21-102	CFT	1
L5	VQR7002-302	RF Coil	sw	1	BPT	VBP4M3B-001	Band Pass Filter	1
L6	VQL7T19-301	OSC Coil	LW	1	LPF	VQZ0020-001	Low Pass Filter	1
L7	VQM7U01-301	"	MW	1	IC1	AN7213	IC	1
L8	VQR7002-302	"	sw	\| 1 \|	IC2	AN7222N	"	1
L9	V03047-21	Coil		1	IC3	AN7410N	"	1

Page 20

RC-770 L/LB/LD/LS

Remarks

47 Ω 1/6 W 220 kΩ ″ 68 Ω ″

1 kΩ

47 Ω 3.3 kΩ 470 Ω

3.9 kΩ

27 κΩ 470 Ω 100 κΩ 1 κΩ

2.2 kΩ

Q'ty

Parts Name

C. Resistor

▲ parts are safety assurance parts. When replacing those parts, make sure to use the specified one.

A parts are safety assurance parts.

Enclosure Assembly and Electrical Parts List When replacing those parts, make sure to use the specified one.

Ref. No.	Parts No.	Parts Name	Remarks	Q'ty	Ref. No.	Parts No.
Q1	2SC1359(C)	Si. Transistor		1	R11	QRD161J-470
Q2	2SC828(Q,R)	"		2	R12	″ -22
D1	MA165	Si. Diode		2	R13	″-68 ″68
D2 S1-1~8	1S553T QSS8401-101	Slide Switch		8	R15	-68
57	0551201-026	"		1	B17	"-47
C1	QCS11HJ-100	C. Capacitor	10 pF 50 V	1	R18	″ -33
C2	QCF11HP-223	"	0.022µF ″	1	R19	″-47
C3	QCS11HJ-240	"	24 pF "	1	R21	″-47 ″-39
C5	UC105CH-150	"	IS pr	1	R22	-39
C6 C7	-5R0 OCT05UJ-5B0	"	5 pF "	1	R24	-22
C8	QCF11HP-103	"	0.01 μF ″	1	R26	″-47
C9	QCT05CH-150	"	15 pF ″	1	R27	"-10
C10	QCY11HK-472	"	0.0047µF "		R28	-10
C11	QCF11HP-223	"	0.022 μF 50 V	1	R29	// -18 // -22
C12		"	0.01 μF 47 nF ″		R32,33	-22
C14	″ -390	"	39 pF ″	1	1104	10
C16	″ -120	"	12 pF ″	1
C17	″ -8R0	"	8 pF ″	1
C18	" -100	"	10 pF ″	1
C19	-470		47 pF ″
C20	OCT05WK-120	"	12 pF "	1
C22	// PPO	"	8 pF	1
C22	OCS11HJ-150	"	15 pF 50 V	1
C24	QFP42AJ-151	P.P. Capacitor	150 pF	1
C25	″ -361	"	360 µF	1
C26	″ -392	"	0.0039 μF	1
C27	QCS11HJ-150	C. Capacitor	15 pF 50 V	1
C28	QCF11HP-223	"	0.022μF50 V
C30	0CC11EM-223	"	0.022 µF ″	1
C31	QCF11HP-103	"	0.01 μF ″	1
C32	QET41AR-476	E. Capacitor	47 μF 10 V	1
C33	QEN41EM-475	"	4.7 μF 25 V	1
C34	QET41HR-105		1 μF 50 V
C35,36	0CC11FM-223		0.022 μF	1
C28	0001111121	"	120 pE 50 V	1
C39	QCC11EM-223	"	0.022 µF 25 V	1
C40,42,43	QET41ER-106	E. Capacitor	10 μF ″	3
C45	QET41AR-476	"	47 μF 10 V	1
C46	QCF11HP-223	C. Capacitor	0.022 µF 50 V	1
C48	QET41HR-105	E. Capacitor	1 μF ″
C49	0CE11HP-223		0.022 µF 50 V
C51~53	QET41HR-474	E. Capacitor	0.47 μF ″	1
C54	QFP42AJ-471	P.P. Capacitor	470 pF	1
C56,57	QCC11EM-153	C. Capacitor	0.015µF25 V	2
C58,59	QET41HR-475	E. Capacitor	4.7 μF 50 V	2
C60	-105 05741AD 477	,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,	1 μF ^" 470 μF 10 V	1
C63	QCT05CH-3R0	"	3 pF 16 V	1
CN1	E04365-004	Connector		1
R1	QRD161J-101	C. Resistor	100 Ω 1/6 W	1
R2	″ -271	"	270 Ω ″	\| 1 \|
R3	″ -393	"	39 kΩ ″
R4	-184		180 KW
R5	-471	"	470 Ω ″ 100 kΩ ″
\| H6 \| B7	-104 ″104	"	//// K12
R8	″ -470	"	47Ω ″	1
R9	″ -470	"	" "	1
R10	″ -101	"	100 Ω ″	1

Ref. No.	Parts No.	Parts Name	Remarks	Q'ty
1~2 1 ″	ZCRC770Y-CBF VJC1289-010A ″-104	Front Cabinet Ass'y Front Cabinet	RC-770L/LB RC-770LD/LS	1 1 1
2 3 4 ″	VJD3409-001 VJD3410-001 VJK3211-004 ″-003	Punching Panel Control Plate Dial Scale	RC-770L/LB/LS RC-770LD	2 1 1 1
5 6 7 ″	VJD3411-001 VJD3412-001 VJK3210-002 ″001	Control Plate LED Lens Dial Lens	RFC-770L/LB RC-770LD/LS Woofer	1 1 1 1 2
9	SBSF3008Z	Screw	for Speaker	8
10 11 12 13 14	EFB-S77D41 VYH4832-002 GBSF3020Z VYH4034-002 VYH4032-001	Speaker Dial Dram Screw Stud Roller	Tweeter for Dial Dram for Roller	2 1 1 2 2
15 16 17 18	VJN4081-001 VHR2TK9-05AT 50153-3 VYH5270-001	Pointer Dial Cord Spring Tuning Bushing	for Cord	1 1 set 1 1
19 20 21 22 23	SBSF3010Z VYH4027-006 REE4000X VXS4109-001 VXQ3038-001	Screw Tuning Shaft E-ring Slide Knob Toggle Lever	for Tuning Bushing for T. Shaft for Stereo-Mono for Band	2 1 1 1 1
24 25 26 27 28	VYH5269-001 SBSF3020C VYH5267-001 SSSP2608 VYH5274-001	Lever Holder Screw Arm Screw Connector	for Tuner ~ Cabinet	1 5 1 1 1
29 30 31 32 33	VMME62N-031 VYH4043-002 VYH5271-001 WNS2600Z NTB2600	E.C. Mic Special Screw Rec Lever Washer Nut		2 1 1 2 1
34 35 36 37 38	VYH4348-001 VYH5268-001 SBSF3014Z VXQ4058-001 VXQ4109-001	Mic Busing Bridge Screw Lever Cap Slide Knob	Tap→ Radio Dolby	2 4 3 1 1
39 40 41 42	SPSP3006C WBS3000 SBSF3010C	Screw T. Lock Washer Screw	Mecha ~ Amp Mecha ~ Cabinet Amp ~ Cabinet	1 1 6 3
43	VTP48N2-90F VTP48C2-90FBS		T701 RC-770LB	1
44 45-1 45-2 46	QMF51A2-R80 * -R80BS SBSF3014Z GBSF3020C VJC1290-104 *	Fuse Screw Rear Cabinet	RC-770L/LD/LS RC-770LB Power P.W.B. Power Transformer RC-770L/LB	1 1 2 1
47 48	VJA3006-00C VYH5278-001	Telescopic Antenna Ant Contact
49 50 51 52 53	SDSP3012R VJH4036-00C VYSS2R3-002 VYH4696-001 VYH5279-001	Screw Handle Ass'y Spacer Spring Battery Spring	for Antenna for Handle	1 1 2 2 1
54 55 56 57 58	VYH5280-002 SBSF3020R VJC2016-006 VYSH108-016 VYN5089-009 ″-007 ″-011	Battery Contact Screw Battery Cover Spacer Name Plate	Front ~ Rear for Battery Cover RC-770LB RC-770LD/LS RC-770LS	1 7 1 1 1 1
59 60	VJT3115-00A VYH4941-002	Door Ass'y Door Spring		1

Page 21

Enclosure Assembly and Electrical Parts

nel. NO.	Faits NO.	Faits Maine	nemarks	ury
61 62 63 64 65	VXL4193-001 VXL4107-101 VXL4194-001 Q03095-206 VYH5381-001	Tuning Knob Knob Fine Knob Washer Spring Connector		1 3 1 3 1
66 67 68 69	VYH5276-001 LPSP2604Z VKZ4001-010 VYTH417-001	Rec. Spring Plate Screw Wire Holder Blind		1 1 3 1

Ref. No.	Parts No.	Parts Name	Remarks	Q'ty
70 71 72 73 74	VYSA1R4-050	Spacer ″ Shield Spacer		4 3 4 1 1
75 76 77	VYSH104-022 VXP4378-001 VYH5472-001	″ Push Knob Bracket	RC-770LD ″ for DIN Jack	1 1 1

(No. 1531) 21

RC-770 L/LB/LD/LS

Page 22

Fig. 29 (No. 1531) 22

Page 23

Mechanical Component Parts List

A parts are safety assurance parts. When replacing those parts, make sure to use the specified one.


Ref. No.	⚠	Parts No.	Parts Name	Remarks	Q'ty
1		180001501ZT	Mecha. Chassis Ass'y		1
2		18000201T	Rec. Safety Lever		1
3		18000316T	Head Panel		1
4		18000305T	Head Base
5		18000330521	Detector Plate Ass'y		1
6		VGH0421-010	R/P Head		1
		14400315T	Head Spring		2
8		V03078-046	E. Head Binch Bollor Arm Ass'y
10		18000405T	Pinch Boller Spring		1
10		100004001			1
		18000530121 18000508T	Back Tension Spring		1
13		1800053027T	Supply Reel Ass'y
14		18000516T	Back Tension Spring		1
15		180006310ZT	RF. Cluth Ass'y		1
17		180006503ZT	Take-up Roller Arm Ass'v		1
18		18000635T	Take-up Roller		1
19		18000609T	Collar		1
21		18000610T	F.F. Gear		1
22		180007312ZT	Flywheel Ass'y		1
24		15100134T	Pack Spring		1
25-1		18000934	Button Base (R)		1
25-2		18000935B	(L)		1
26		18000902T	Rec. Button Lever
21		180009041	Play Button Lever
28		18000906T	Rew. Button Lever
29		180009081	F.F. Button Lever		1
30		180009091	Stop Button Lever		1
32		1800093107T	Lock Plate Ass'v		1
22		170009217			1
34		18000917T			1
35		VXP3081-001	Push Button	for Play	1
36		VXP3082-001	"	for Pause	\| 1 \|
37		″ -002	"	for Stop/Eject	1
38		″ -003	"	for F.F.	1
39		″ -004	"	for Rew.	\| 1 \|
40		VXP3083-002		for Rec.
41		18000918T	Flange Cup Screw		6
42		18001032721
43		18001033T	Motor Bracket
		58809101	Rubber Cushion		3
45		120012011 15221202T	Mat		2
47		4081203T	Main Belt		1
48		12221702T	Pause Lever		1
49		18201032T	Pause Stopper
50		18001310T	Counter Bracket
51		18001102T	Eject Slide Lever		1
52	L	17000310T	Collar Screw		1
53		VKC5169-001S	Tape Counter
54		2111202T	Counter Belt
55		LSA-1120C01T	Leaf Switch
\| 70		97870000T	Polyslider Washer	for Capstan	1
71		07760000T	"	($\vec{\vec{\vec{\vec{\vec{\vec{\vec{	1
		377000001		(d2.05 x d8 x t0.5)
70		042100007	Polyolidor Washer
/2		942100001		for F F Gear × 1	2
				($\phi1.2 \times 63 \times t0.25)
73		15601501T	Washer	B/P Head ($\phi_1 1 \times \phi_5 \times t_0 4)	1 1

Page 24

A parts are safety assurance parts.

When	replacing	those	narts.	make	sure	to use	e the	specified one.
*****	ropiaonig	11000	001.001	11 June O	ouro

Ref. No.	Parts No.	Parts Name	Remarks	Qʻty
74	16100604T	Polyslider Washer	for Supply Reel Ass'y × 1 for Take-up Reel Ass'y × 1 (\u03c61.6 × \u03c63.8 × t0.3)	2
75	18000907T	Spring	for FF Button	1
76	18000608⊤		for Take-up Roller Arm	1
77	18000903T	"	for Rec. Button	1
78	18000957T		for Play Button	1
79	18000905T	"	for Rew. Button × 1	1
80	18000903T		for Stop Button	1
81	18000957T	" "	for Pause Button
82	180009191	"	for Thrust Spring	1
83	180007071
84	18000961T	"	for Auto Lever	1
85	180009581		for Figet Slide Lover	1
80	180011281 200726040T	Tan Screw	for Peak Spring x 1 Mat x 2	3
88	17152015T	Stopper	for Pinch Roller Arm Ass'v	1
89	SPSD2004Z	TH. Tap. Screw	for Take-up Roller × 1, Button Base × 2	3
90	SPSE20067	Tap. Screw	for Leaf Switch	1
92	SPSX2007Z	PM. Screw	for R/P Head	1
93	98210000T	Screw		2
97	98200000T	Cap Screw	for R/P Head	1
98	13270412AT	U Washer	for E. Head	1
99	93330000T	Washer	for E. Head	\| 1
			(\phi 2.4 \times \phi 7 \times t0.2)
100	18001404T	RC Spring
102	180003091		Tor Head Panel
103	986100001	in. rap. Sciew
106	18001127T	Collar	for Eject Slide Lever
107	SPSD3008Z	IH. Tap. Screw
108	33373000Z	BE Pulley Arm Stopper
110	97180000231	Collar Screw	for Button Base	1

Page 25

RC-770 L/LB/LD/LS

Packing

Packing Material Parts List

Ref. No.	Parts No.	Parts Name	Remarks	Q'ty
1	VPD5089-J01	Carton	RC-770LB	1
	″ -J04	"	RC-770L	1
	″ -J08	"	RC-770LD	1
	″ -J10	"	RC-770LS	1
2	VPH1269-001	Side Cushion (L)		1
3	VPH1270-001	″ (R)		1
5	QPGA012-01505	Poly Bag	for Power Cord	1
6	QPGB017-02404	"	for Instruction Book	1
7	VPE3002-008	"	RC-770LB	1
	QPGA070-04005	"	RC-770L/LD	1
8	VPH4101-006	Door Protector		1

Page 26

Accessories

Parts No.	Parts Name	Remarks	Qʻty
VNM0906-301	Instruction Book	RC-770L/LB	1
VNF0903-001	Feature Tag	RC-770L/LB	1
VNF0904-001	"	RC-770LD	1
BT20013C	Guarantee Certificate	RC-770LB	1
QMP3950-183	Power Cord	RC-770L/LD	1
QMP9017-009BS	"	RC-770LB	1
QZL1002-003	Warning Label	RC-770LB	1
31465-18	Mark	RC-770LB	\| 1
VPZ4001-001	Serial Ticket		\| 1
BT20054-003A	Caution Card	RC-770LD	\| 1
BT20065	Warranty Card	"	1
BT20066	"	"	1
VNM0906-302	Instruction Book	RC-770LD/LS	1
VGT12S2-J05	Cassette Tape	RC-770LS	\| 1

JVC RC-770 L, RC-770LB, RC-770LD, RC-770LS SERVICE MANUAL

Contents

Specifications

Safety Precautions

▲ Safety mark

Locations of Controls

Locations of Main Parts

How to Engage Dial Cord

Removal of the Main Parts

Rear Cabinet and Telescopic Antenna (Fig. 8)

Tuner P.W. Board (Fig. 9)

Amp P.W. Board (Fig. 9)

Power supply P.W. Board (Fig. 9)

Control P.W. Board (Fig. 9)

Mechanism assembly (Fig. 10)

Speaker (Fig. 10)

LED P.W. Board (Fig. 11)

Mechanism Parts

Adjustment of Cassette Mechanism

Tuner Alignment

BASIC CONDITIONS

FM MPX Alignment

Parts Arrangement for Alignment

Dummy Antenna

Adjustment of Cassette Recorder Amplifier

Block Diagram

Tuner Signal Diagram

Play Back System

Fig. 19

Amplifier P.W. Board Parts and Parts List

Other P.W. Board Parts List

DIN P. W. Board (RC-770LD/LS)

Amp. P.W. Board (RC-770LD/LS)

DIN P. W. Board (RC-770LD/LS)

Amp. P.W. Board Parts List (RC-770LD/LS)

Tuner P.W. Board Only Parts List (RC-770LD/LS)

Tuner P.W. Board Parts List (RC-770L/LB)

Enclosure Assembly and Electrical Parts List When replacing those parts, make sure to use the specified one.

Mechanical Component Parts List

Packing

Packing Material Parts List

Accessories