Jvc RX 5020 VBK Service Manual

Page 2

RX-5020VBK/RX5022VSL

-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 (/i\) 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 reassembling 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 a return
path to the chassis, to a known good earth ground. Any leakage current must not exceed 0.5mA AC (r.m.s.).

0 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 1,500 Q10W resistor paralleled by a 0.15M F AC-type capacitor

between an exposed metal part and a known good earth ground. AC VOLTMETER
Measure the AC voltage across the resistor with the AC a (Having1000
voltmeter. ohms/volts, .. .
Move the resistor connection to each exposed metal part, c °m°'e sens'WW)

particularly any exposed metal part having a return path to
the chassis, and meausre the AC voltage across the resistor.

0.1511 F AC TYPE

Now, reverse the plug in the AC outlet and repeat each -"| P'aceihis
measurement. Voltage measured any must not exceed 0.75 V W . e :géfieeigosed
AC (r.m.s.). This corresponds to 0.5 mA AC (r.m.s.). 15009 10W metal part.
Good earth ground
-Warning A CAUTION

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.

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.

In regard with component parts appearing on the silk-screen printed side (parts side) of the PWB diagrams, the
parts that are printed over with black such as the resistor (-), diode (h) and ICP (Q) or identified by the "A"

mark nearby are critical for safety.
(This regulation does not correspond to J and C version.)

Page 21

RX-5020VBK/RX5022VSL

lTC9446F-025 (l0631) : Digital signal processor for dolby digital (AC-3)

/ DTS audio decode

Pin No. Symbol l/O Function
1 W | Reset signal input terminal (L:reset H: normal operation)
2 MIMD | Microcomputer interface mode selection input terminal (L:seria| H:|C bus)
3 MIKE | Microcomputer interface chip select input terminal
4 W | Microcomputer interface latch pulse input
5 MIDIO l/O Microcomputer interface data I/O terminal
6 W | Microcomputer interface clock input terminal
7 MIACK O Microcomputer interface acknowledge output terminal
8~t1 F|0~3 | Flag input terminal 0~3
12 IRQ | Interrupt input terminal
13 V88 - Digital ground terminal
14 LRCKA | Audio interface LR clock input terminal A
15 BCKA | Audio interface bit clock input terminal A
16~18 SDOO~2 0 Audio interface data output terminal 0
19 SD03 - Non connect
2O LRCKB | Audio interface LR clock input terminal B
21 BCKB | Audio interface bit clock input terminal B
22 SDTO | Audio interface data input terminal 0
23 SDT1 | Audio interface data input terminal 1
24 VDD - Power supply for digital circuit
25 LRCKOA 0 Audio interface LR clock output terminal A
26 BCKOA 0 Audio interface bit clock output terminal A
27,28 W | Test input terminal 0/1 (thest H: normal operation)
29~30 LRCKOB,BCKOB - Non connect
31 TXO O SPDIF Output
32,33 TEST2,3 | Test input terminal (thest H: normal operation)
34 RX | SPDIF input terminal
35 V88 - Ground terminal for digital circuit
36 TSTSUBO | Test sub input terminal 0 (L:test H: normal operation)
37 FCONT O VCO Frequency control output terminal
38,39 TSTSUB1,TSTSUB2 | Test sub input terminal 1,2 (L:test H: normal operation)
40 PDO 0 Phase detect signal output terminal
41 VDDA - Power supply for analog circuit
42 PLON | Clock selection input terminal (L:external clock H:VCO clock)
43 AMPI | amplifier input terminal for LPF
44 AMPO O amplifier output terminal for LPF
45 CKI | External clock input terminal
46 VSSA - Ground terminal for analog circuit
47 CKO O DIR Clock output terminal
48 LOCK O VCO Lock output terminal
49 m - Ground terminal for digital circuit
50 W 0 External SRAM writing signal output terminal
51 E 0 External SRAM output enable signal output terminal
52 CE 0 External SRAM chip enable signal output terminal
53 VDD - Power supply terminal for digital circuit
54~61 IO7~0 l/O External SRAM data l/O terminal 7~0
62 V88 - Ground terminal for digital circuit
63~70 ADO~7 0 External SRAM address output terminal 0~7
71 VDD - Power supply terminal for digital circuit
72~80 AD8~16 0 External SRAM address output terminal 8~16
81 VSS - Ground terminal for digital circuit
82~89 POO~7 0 General purpose output terminal 0~7
90 VDDDL - Power supply terminal for DLL
91 LPFO O LPF output terminal for DLL
92,93 DLON,DLCKS | Refer to the undermentioned table
94 SCKO - Non connect
95 VSSDL - Ground terminal for DLL
96 SCKI | External system clock input terminal
97 VSSX - Ground termonal for oscillation circuit
98,99 XO,X| l/O Oscillation I/O terminal
100 VDDX - Power supply terminal for oscillation circuit
DLCKS terminal DLONterminaI DLL clock setting
L L SCKI input (DLL circuit OFF)
L H Four times XI clock
H L Three times XI clock
H H Six times XI clock

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