Jvc RVB 70 GY Service Manual

Page 1

RV-B70GY/RV-B7OAG

JVB
SERVICE MANUAL

RV-B7OGY/RV-B7OAG

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.QQ.P.'SZk.UP. Area Suffix
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Lsi B ............ the UK
................. E - - , Continental Europe
MN3551O EN ------- North Europe
CD _ EE ------ Eastan Europe
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DIGITAL AUDIO
Contents
Safety Precautions ----------------------- 1-2 Flow of Functional Operation
Instruction Book --------------------------- 1-6~26 Until TOC Read -------- 2-17
Description of Major ICs **************** 2-1 Wiring Connection ----------------------- 2-18
Main parts Layout ---------------------- 2-8 Schematic Diagrams ------------------- 2-19
Disassembly Procedures -------------- 2-10 Printed Circuit Boards ----------------- 2-24~26
Adjustment Procedures ---------------- 2-15 Parts List ----------------------------------- 3-1- 23

,
No.20684
COPYRIGHT© 1998V|CTOR COMPANY OF JAPAN, LTD.

MAR. 1998

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RV-B70GY
RV-B7OAG

-Safety Precautions

1.This design of this product contains special hardware and many circuits and components specially
for safety purposes. For continued protection, no changes should be made to the original design
unless authorized in writing by the manufacturer. Replacement parts must be identical to those
used in the original circuits. Services should be performed by qualified personnel only.

2. Alterations of the design or circuitry of the product should not be made. Any design alterations of
the product should not be made. Any design alterations or additions will void the manufacturers
warranty and will further relieve the manufacture of responsibility for personal injury or property
damage resulting therefrom.

3. Many electrical and mechanical parts in the products have special safety-related characteristics.
These characteristics are often not evident from visual inspection nor can the protection afforded
by them necessarily be obtained by using replacement components rated for higher voltage,
wattage, etc. Replacement parts which have these special safety characteristics are identified in
the Parts List of Service Manual. Electrical components having such features are identified by
shading on the schematics and by (A) on the Parts List in the Service Manual. The use of a
substitute replacement which does not have the same safety characteristics as the recommended
replacement parts shown in the Parts List of Service Manual may create shock, fire, or other
hazards.

4.The leads in the products are routed and dressed with ties, clamps, tubings, barriers and the
like to be separated from live parts, high temperature parts, moving parts and/or sharp edges
for the prevention of electric shock and fire hazard. When service is required, the original lead
routing and dress should be observed, and it should be confirmed that they have been returned
to normal, after re-assembling.

5. Leakage currnet check (Electrical shock hazard testing)

After re-assembling the product, always perform an isolation check on the exposed metal parts

of the product (antenna terminals, knobs, metal cabinet, screw heads, headphone jack, control

shafts, etc.) to be sure the product is safe to operate without danger of electrical shock.

Do not use a line isolation transformer during this check.

0 Plug the AC line cord directly into the AC outlet. Using a "Leakage Current Tester", measure
the leakage current from each exposed metal parts of the cabinet,particularly any exposed
metal part having areturn path to the chassis, to a known good earth ground. Any leakage
current must not exceed 0.5mA AC (r.m.s.)

.Alternate check method
Plug the AC line cord directly into the AC outlet. Use an AC voltmeter having, 1,000 ohms
per volt or more sensitivity in the following manner. Connect a 1,5009 10W resistor paralleled by

a 0.15uF AC-type capacitor between an exposed

metal part and a known good earth ground. fixgghggg-ER
Measure the AC voltage across the resistor with the 7 ohms/volts,

AC voltmeter. or more sensitivity)
Move the resistor connection to eachexposed metal °

part, particularly any exposed metal part having a 0_15uF AC TYPE

return path to the chassis, and meausre the AC ,
voltage across the resistor. Now, reverse the plug in -"- 32:23?
the AC outlet and repeat each measurement. voltage Jer = each exposed
measured Any must not exceed 0.75 V AC (r.m.s.). 1500;) low metal pan.

This corresponds to 0.5 mA AC (r.m.s.).
Good earth ground

- Warning

1.This equipment has been designed and manufactured to meet international safety standards.

2. It is the legal responsibility of the repairer to ensure that these safety standards are maintained.
3. Repairs must be made in accordance with the relevant safety standards.

4. It is essential that safety critical components are replaced by approved parts.

5. If mains voltage selector is provided, check setting for local voltage.

A CAUTION 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.

//\

/\

Page 27

RV-B70GY
RV-B70AG

Discription of Majar le
I MN171603J82(ICQO1) : System controller

1. Layout 20

~ 1
21 80
z x
40 61
41 ~ 60
2.Terminal Function

Pin - Pin
No. Symbol I/O FUTCIO" No, Symbol l/O Function
1 VOL1 I volume encoder input 43 ITADOOR | Version detect
2 VOL2 | Volume encoder input 44 STTA 0 Output for TAPE control(Strobe signal output)
3 AVSS ' Connected to GND 45 NVVDL1 0 Super woofer volume output
4 SAFETYt l ADO(FtEG SAFETY)input 46 /WVDL2 0 Super woofer volume output
5 SAFETYZ I AD1 input 47 /WVDL3 0 Super woofer volume output
6 sass/noon | A02 input 48 SCT 0
7 KEY | AD$(Key) input 49 NC - Not use
8 VERSION 1 AD4(VERSION) input 50 POUT 0 System power supply control output
9 KEY1 | ADSITAPEO) input 51 IBCTL 0 Analog power supply control output
10 BATT i AD6(BATT) input 52 PBMUTE 0 Output for TAPE oontrol(play mute)
11 mews I AD7(TEMP SAFETY) input 53 /SMUTE 0 System mute Output
12 AVdd ~ A/D converter reference voltage input 54 /FAUX O AUX function control
13 VLCD1 - LCD power supply input 55 FI'U 0 Tuner function control
14 VLCD2 - LCD power supply input 56 POD 0 CD function control
15 VLCD3 ~ LCD power supply input 57 VOL 0 PWM(main volume) 0let
16 CDM3 0 LCD common output 58 BASS O PWM(BASS) output
17 CDM2 0 LCD common output 59 THE 0 PWM(TREBLE) output
18 CDM1 0 LCD common output 60 PLAV | input for TAPE controI(PLAY detect)
19 CDMO 0 LCD common output 61 AC/DC I Input for System power supply detect
20 SEGO 0 LCD segment 0 output 62 BUP I Input for Backup detect
21 SEG1 0 LCD segment 1 output 63 STAT I Input for CD control(status)]
22 SE62 0 LCD segment 2 output 64 XRST 0 Output for CD controlICD-LSi reset)
23 SE63 0 LCD segment 3 output 55 MLD 0 Output for CD oontrol(Micon data road)
24 SEG4 0 LCD segment 4 output 55 MCLK 0 Output for CD oontrol(Micon clock)
25 SEC-.5 0 LCD segment 5 output 57 MDATA 0 Output for CD control(Micon data)
26 SEGS 0 LCD segment 6 output 68 IRESET | System reset input/output
27 SEG7 0 LCD segment 7 output 69 X1 . X'tai Oscillator for timer/sub system clock
28 SEG8 0 LCD segment 8 output 70 X0 - X'tal Oscillator for timer/sub system clock
29 SEGQ 0 LCD segment 9 output 71 Vss . Connected to GND
30 SEG10 0 LCD segment 10 output 72 0802 - X'taI/Ceramic Oscillator for system clock
31 SEG11 0 LCD segment 11 output 73 0301 . X'tal/Ceramic Oscillator for system clock
32 SEG12 0 LCD segment 12 output 74 Vdd _ +Power supply
33 SEG13 0 LCD segment 13 output 75 BEAT 0 Output for beat out control
34 SEG14 0 LCD segment 14 output 75 SOCK l Output for CD control(C|ock for sub-Q)
35 SEGts 0 LCD segment 15 output 77 SUBQ I Input for CD control(Data for sub-Q)
36 SEG16 0 LCD segment 16 output 78 PERIOD 0 Output for Tuner control(Strobe signal)
37 SEG17 0 LCD segment 17 output 79 /HPX I Input for Tuner controI(Stereo signal)
38 SEG15 0 LCD segment 18 output 80 SCK 0 Serial clock(sifl back)inputloutput
39 SEG19 0 LCD segment 19 output 81 SI I Serial data(sift back B)input
40 WVOL1 I Super woofer volume encoder input 82 SO 0 Serial data(sift back B)0UtPUt
41 WVOL2 I Super woofer volume encoder input 33 IREM I Remoncontrol signal input/output
42 REEL I Input for TAPE control (TAAPE end detect) 84 /p|N r Power key input/output