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Extracted text from Jvc MXGT 88 Service Manual (Ocr-read)
Page 1
MX-GT88
1-2
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 manufacturer`s 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 ( ) 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.
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.).
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 10W resistor paralleled by a 0.15 F AC-type capacitor
between an exposed metal part and a known good earth ground.
Measure the AC voltage across the resistor with the AC
voltmeter.
Move the resistor connection to each exposed metal part,
particularly any exposed metal part having a return path to
the chassis, and meausre the AC voltage across the resistor.
Now, reverse the plug in the AC outlet and repeat each
measurement. Voltage measured any must not exceed 0.75 V
AC (r.m.s.). This corresponds to 0.5 mA AC (r.m.s.).
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.
Good earth groundPlace this
probe on
each exposed
metal part. AC VOLTMETER
(Having 1000
ohms/volts,
or more sensitivity)
1500 10W 0.15 F AC TYPE
!
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 ( ) and ICP ( ) or identified by the " "
mark nearby are critical for safety.
(This regulation does not correspond to J and C version.)
Page 2
1-3
MX-GT88
1. Service should be performed by qualified personnel only.
2. This equipment has been designed and manufactured to meet international safety standards.
3. It is the legal responsibility of the repairer to ensure that these safety standards are maintained.
4. Repairs must be made in accordance with the relevant safety standards.
5. It is essential that safety critical components are replaced by approved parts.
6. If mains voltage selector is provided, check setting for local voltage.
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.
2. Any unauthorised design alterations or additions will void the manufacturer's guarantee ; furthermore the
manufacturer cannot accept responsibility for personal injury or property damage resulting therefrom.
3. Essential safety critical components are identified by ( ) on the Parts List and by shading on the
schematics, and must never be replaced by parts other than those listed in the manual. Please note
however that many electrical and mechanical parts in the product have special safety related
characteristics. These characteristics are often not evident from visual inspection. Parts other than
specified by the manufacturer may not have the same safety characteristics as the recommended
replacement parts shown in the Parts List of the Service Manual and 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.
!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.
(U.K only)
Page 29
MX-GT88
1-30
LC876764 (UIC1) : Microcontroller
1.Pin layout
S48/PG0
S49/PG1
S50/PG2
S51/PG3
P00
P01
P02
P03
VSS2
VDD2
P04
P05
P06
P07
P10/SO0
P11/SI0/SB0
P12/SCK0
P13/SO1
P14/SI1/SB1
P15/SCK1
S47/PF7
S46/PF6
S45/PF5
S44/PF4
S43/PF3
S42/PF2
S41/PF1
S40/PF0
VDD4
S39/PE7
S38/PE6
S37/PE5
S36/PE4
S35/PE3
S34/PE2
S33/PE1
S32/PE0
S31/PD7
S30/PD6
S29/PD5
S28/PD4
S27/PD3
S26/PD2
S25/PD1
S24/PD0
S23/PC7
S22/PC6
S21/PC5
S20/PC4
FIX0 P16/T1PWML
P17/T1PWMH/BUZ
P30/INT4/T1IN
P31/INT4/T1IN
P32/INT4/T1IN
P33/INT4/T1IN
P34/INT5/T1IN
P35/INT5/T1IN
P36/INT5/T1IN
P37/INT5/T1IN
RES
XT1/AN10
XT2/AN11
VSS1
CF1
CF2
VDD1
P80/AN0
P81/AN1
P82/AN2
P83/AN3
P84/AN4
P85/AN5
P86/AN6
P87/AN7/MICIN
P70/INT0/T0LCP/AN8
P71/INT1/T0HCP/AN9
P72/INT2/T0IN/NKIN/AN12
P73/INT3/T0IN/AN13
S0/T0
S19/PC3
S18/PC2
S17/PC1
S16/PC0
VDD3
S15/T15
S14/T14
S13/T13
S12/T12
S11/T11
S10/T10
S9/T9
S8/T8
S7/T7
S6/T6
S5/T5
S4/T4
S3/T3
S2/T2
S1/T1 81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
10050
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31 80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
2.Block diagram
IR PLA
PC
Port 0
Port 1
SIO0
SIO1
VFD Controll er
Port 3
Port 7
Port 8
AD C
ACC
PSW
RAR
RAM
AL U
Ti mer 6
Ti mer 7
Ti mer 4
Ti mer 5
CF
RC
Xtal
MRC Interrupt Control
Stand-by Control ROM Clock
Generator
Bus Interface
Timer 0
(High speed clock counter)
Timer 1
Base Timer
INT 0 - 5
Noise Rejection Weak Signal
Detector
Stack Pointer
Watch Dog Timer C Register B Register
Description of major ICs
(No.22075)
MX-GT88
VICTOR COMPANY OF JAPAN, LIMITED
AV & MULTMEDIA COMPANY AUDIO/VIDEO SYSTEM CATEGORY 10-1,1 chome,Ohwatari-machi,maebashi-city,371-8543,Japan
Printed in Japan
200307
