CONTENTS |
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PAGE |
Safety Instructions |
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2 |
Technical Specifications |
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3 |
Block Diagram |
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4 |
Pin Voltages of IC’s |
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5 |
Oscillograms |
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8 |
Electrical and Service Adjustments |
12 |
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Part List |
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15 |
Circuit Diagrams |
Attached |
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SAFETY INSTRUCTIONS
GENERAL GUIDELINES
1.It is advised to insert an isolation transformer in the AC supply before servicing a hot chassis.
2.Potentials as high as 33KV are present when this receiver is in operation. Operation of the receiver without the rear cover involves the danger of a shock hazard from the receiver power supply. Servicing should not be attempted by any one who is not competent with the precautions necessary when working on the high voltage equipment. Always discharge the anode of the tube.
3.When servicing observe the original lead dress in the high voltage circuits. If a short circuit is found, replace all the parts which have been overheated or damaged by the short circuit.
4.Always use the manufacturer’s replacement safety components. The critical safety
components marked with 
on the schematics diagrams should not be replaced by other substitutes. Other substitute may create the electrical shock, fire or other hazards. Take attention to replace the spacers with the originals. Furthermore where a short circuit has occurred, replace those components that indicate evidence of overheating.
5.After servicing, see that all the protective devices such as insulation barriers, insulation papers, shields and isolation R-C combinations are correctly installed.
6.When the receiver is not being used for a long time of period of time, unplug the power cord from the AC outlet.
7.After servicing make the following leakage current checks to prevent the customer from being exposed to shock hazard.
LEAKAGE CURRENT COLD CHECK
1.Unplug the AC cord and connect a jumper between the two prongs of the plug.
2.Turn the receiver’s power switch on.
3.Measure the resistance value with an ohmmeter, between the jumpered AC plug and each exposed metallic cabinet part on the receiver, such as screw heads, aerials,
connectors, control shafts etc. When the exposed metallic part a return path to the chassis the reading should be between 4Mohm and the 20Mohm. When the exposed metal does not have a return path to the chassis, the reading must be infinite.
LEAKAGE CURRENT HOT CHECK
1.Plug the AC cord directly in to the AC outlet. Do not use an isolation transformer for this check.
2.Connect a 2Kohm 10W resistor in series with an exposed metallic part on the receiver and an earth, such as a water pipe.
3.Use an AC voltmeter with high impedance to measure the potential across the resistor.
4.Check each exposed metallic part and check the voltage at the each point.
5.Reverse the AC plug at the outlet and repeat each of the above measurements.
6.The potential at the any point should not exceed 1.4 Vrms. In case a measurement is outside the limits specified, there is the possibility of a shock hazard, and the receiver should be repaired and rechecked before it is returned to the customer.
HOT CHECK CIRCUIT
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AC-Voltmeter |
TO INSTRUMENTS |
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EXPOSED |
Water pipe |
METALLIC PARTS |
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(earth) |
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2 K Ohm |
Figure 1
X-RAY RADIATION WARNING
The primary source of X-ray radiation in this receiver is the picture tube. The chassis is specially constructed to limit X-ray radiation. For continued X-ray radiation protection, replace the tube with the same type of the original one.
CAUTION
AFTER REMOVAL OF THE ANODE CAP, DISCHARGE THE ANODE OF THE PICTURE TUBE AND THE ANODE CAP TO THE METAL CHASSIS, CRT SHIELD, OR THE CARBON PAINTED ON THE CRT WITH A HIGH VOLTAGE PROBE AND MULTIMETER (SELECT VDC) AND THEN SHORT CIRCUIT DIRECTLY TO DISCHARGE COMPLETELY.
TECHNICAL SPECIFICATIONS
Power source: |
220-240V AC, 50-60Hz |
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Power consumption (max.) : |
115 W |
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20”, 21” (110W for 21” PF) |
Standby power consumption : |
4 W |
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Aerial impedance : |
75Ohm, coaxial type |
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Receiving system 1: |
PAL BG |
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PAL SECAM BG |
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PAL SECAM BG DK |
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PAL SECAM BG LL’ |
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PAL I |
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Receiving channels: |
VHF BAND I |
CH2-4 |
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VHF BAND III |
CH5-12 |
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CABLE TV |
S1-41 |
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UHF BAND |
CH21-69 |
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Audio outputs : |
2 x 7W RMS at %10 THD |
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High Voltage : |
25 ± 0.5 KV |
20”, 21” |
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Focus voltage : |
%25.6 ± %38 of EHT |
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Grid 2 voltage : |
0-1400 V |
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Heater voltage : |
6.2 ± 0.2 Vrms |
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Video/Audio Terminals : |
AV1 IN |
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Video : 1 Vpp,75 Ohm |
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Audio : 0.5 Vrms, >10 Kohm |
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RGB |
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AV1OUT |
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Video : 1 Vpp, 75 Ohm |
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Audio : 0.5 Vrms, <1 Kohm |
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AV2 IN (optional) |
Video : 1 Vpp,75 Ohm |
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Audio : 0.5 Vrms, >10 Kohm |
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AV2 OUT (optional) |
Video : 1 Vpp, 75 Ohm |
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Audio : 0.5 Vrms, <1 Kohm |
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AV2 IN (RCA, optional) |
Video : 1 Vpp, 75 Ohm |
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Audio : 0.5 Vrms, >10 Kohm |
Operating temperature : |
0-45 Degrees |
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Safety : |
IEC 65 /BS P2N |
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X-Ray radiation : |
ACC. IEC 65/BS P2N |
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1 : TV set is produced to receive “one” of these colour and sound systems.
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Left |
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Left |
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IC317 |
17/14 |
HP |
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IC316 MSP34X0G 29 |
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MSP Reset |
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9/12 |
TDA8944J |
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24 |
Audio Processor |
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Audio |
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Right |
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Tuner |
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28 |
Amp. |
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9 |
10 58 |
55 |
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Right |
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6/8 |
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Intr/ |
Mono in / |
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HP |
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AGC |
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SCL SDA |
IF1 |
IF2 |
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10 |
1/4 |
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QSS |
Aud out |
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Mute (from pin 49 |
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8 |
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13 |
11 |
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of IC402) |
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IC401 |
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EEPROM |
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43 |
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PIF |
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RGB |
T701, T703, |
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30-32 |
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20 |
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7-6 |
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IC101 STV224X |
out |
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T705 |
R |
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19 |
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I2C 51-52 |
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CRT |
G |
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CPT |
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B |
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CVBS-TXT |
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On/Off |
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402 ST92195 |
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33 |
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44 |
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Module |
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Microcontroller |
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(Standby) |
53 |
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Black |
T702, T704, |
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To IC901 |
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45 L/L’ |
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T105,T109 |
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SIF |
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33 |
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T706 |
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LL’ Switch |
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H-sync |
40 |
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1-2 |
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H-Out |
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V-sync |
41 |
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Horizontal |
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15-18 |
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34-37 |
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48 |
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8 |
IC |
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OSD/TXT RGB out + Fast Blanking |
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49 |
H-Sync/LFB |
Deflection |
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BU808DFI |
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Keyboard |
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20/13 |
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Video In/Out |
22/23 |
42 |
47 |
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1 |
47 |
55 |
56 |
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8 |
Audio In/Out |
IC316 |
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V-Amp |
V-Out |
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220V AC in |
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On/off |
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Scart 1 |
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IC901 |
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(Standby) |
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IR |
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Audio In/Out |
IC316 |
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from IC401 |
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TDA16847 |
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Receiver |
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8 |
CVBS/Chroma |
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IC102 |
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Power Supply |
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Audio |
IC316 |
Source |
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Scart 2 |
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SVHS Lum/Chroma |
Select |
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IC501 |
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+13V -13V |
5VA 5VB |
8VA |
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V-Lin |
TDA8174 |
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U1=114V, 33V |
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Vertical |
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16.1 Block Diagram |
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V-Sync to IC402 |
Deflect. |
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PIN VOLTAGES OF IC'S
IC101 (STV2246)
BUS CONTROLLED MULTISTANDARD ONE CHIP TV PROCESSOR
Pin |
Connection |
V DC (*) |
Pin |
Connection |
V DC (*) |
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1 |
Sound IF Input 1 |
1,0 |
29 |
Not connected |
3,9 |
2 |
Sound IF Input 2 |
1,0 |
30 |
Blue Output |
2,3 |
3 |
AGC SIF Capacitor |
0,1 |
31 |
Green Output |
2,2 |
4 |
IF Voltage Reference Filtering |
3,2 |
32 |
Red Output |
2,3 |
5 |
AGC PIF Capacitor |
0,1 |
33 |
Cathode Current Measurement Input |
4,2 |
6 |
Picture IF Input 1 |
2,5 |
34 |
OSD Blue Input |
4,7 |
7 |
Picture IF Input 2 |
2,5 |
35 |
OSD Green Input |
4,8 |
8 |
AGC Tuner Output |
4,6 |
36 |
OSD Red Input |
4,7 |
9 |
IF PLL Filter |
1,2 |
37 |
OSD Fast Blanking |
0,2 |
10 |
IF Ground |
0,0 |
38 |
Cloche Filter Tuning Capacitor |
0,1 |
11 |
AM/FM Mono Sound Output |
4,2 |
39 |
3.5X MHz Crystal |
0,4 |
12 |
5 V IF Supply |
5,1 |
40 |
4.43 MHz Crystal |
- |
13 |
Internal CVBS Output |
3,2 |
41 |
Chroma PLL Filter |
- |
14 |
External Audio Input |
2,5 |
42 |
Vertical Amplitude DAC Output |
4,0 |
15 |
LC Input 1 |
4,0 |
43 |
Chroma/Scanning Ground |
0,0 |
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16 |
LC Input 2 |
4,0 |
44 |
Second Video Switch Output |
4,1 |
17 |
Video/Luma Supply Voltage (8 V) |
8,1 |
45 |
Chroma/Scanning Power Supply (8V) |
8,1 |
18 |
Internal Video Input |
3,7 |
46 |
Beam Current Limiter Control Voltage and |
6,8 |
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Safety Input (XRAY) |
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19 |
Video/Luma Ground |
0,0 |
47 |
Vertical Output Pulse |
4,0 |
20 |
External Video Input |
3,2 |
48 |
Horizontal Output Pulse |
1,4 |
21 |
Black Stretch Capacitor |
2,8 |
49 |
Line Flyback Input and Super-sandcastle Output |
0,7 |
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22 |
Y/CVBSIN3 Y(SVHS) or CVBS3 External Input |
3,2 |
50 |
Scanning PLL Filter |
4,1 |
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23 |
Chroma (SVHS) Input |
1,8 |
51 |
SCL I2C Bus Clock Input |
see osc. |
24 |
Automatic RGB Peak Regulation |
5,0 |
52 |
SDA I2C Bus Data Input |
see osc. |
25 |
External Blue Input |
2,5 |
53 |
Digital Supply Voltage (5 V) |
5,2 |
26 |
External Green Input |
1,7 |
54 |
Digital Ground |
0,0 |
27 |
External Red Input |
2,5 |
55 |
Main Audio Output |
4,0 |
28 |
External Fast Blanking Input |
0,0 |
56 |
FM Demodulation Capacitor |
1,5 |
IC316 (MSP 34XXG)- MULTI STANDARD SOUND PROCESSOR
Pin |
Connection |
V DC |
1 |
Not connected |
2,3 |
2 |
Gnd |
0,0 |
3 |
Gnd |
0,0 |
4 |
Digital control input/output |
0,0 |
5 |
Digital control input/output |
0,0 |
6 |
Gnd |
0,0 |
7 |
Standby (in normal operation it must be high) |
4.9 |
8 |
Not connected |
4.9 |
9 |
SCL |
see osc. |
10 |
SDA |
see osc. |
11 |
Not connected |
0,5 |
12 |
Not connected |
0,5 |
13 |
Not connected |
0,5 |
14 |
Not connected |
0,5 |
15 |
Not connected |
0,5 |
16 |
Not connected |
0,5 |
17 |
ADR Bus Clock Output |
0,5 |
18 |
Digital Circuitry Supply Voltage |
4.9 |
19 |
Digital Circuitry Supply Ground |
0,0 |
20 |
Not connected |
0,5 |
21 |
Not connected (Ground) |
0,0 |
22 |
Not connected (Ground) |
0,0 |
23 |
Not connected (Ground) |
0,0 |
24 |
MSP RESET input |
5,1 |
25 |
Headphone sound output (R) |
0,1 |
26 |
Headphone sound output (L) |
0,1 |
27 |
Reference analog ground |
0,0 |
28 |
Speaker output (R) |
0.1-2.1 |
29 |
Speaker output (L) |
0.1-2.1 |
30 |
Not connected |
0.1-2.1 |
31 |
Not connected |
0.1-2.1 |
32 |
Not connected |
0.1-2.1 |
Pin |
Connection |
V DC |
33 |
Scart 2 sound output (R) |
3.7 |
34 |
Scart 2 sound output (L) |
3.7 |
35 |
Reference analog ground |
0,0 |
36 |
Scart 1 sound output (R) |
3.7 |
37 |
Scart 1 sound output (L) |
3.7 |
38 |
Volume capacitor Headphone |
7,1 |
39 |
Analog Supply High Voltage (8V) |
8,0 |
40 |
Volume capacitor Speaker |
7,1 |
41 |
Ground for Analog Power Supply High Voltage |
0,0 |
42 |
Internal Analog Reference Voltage |
3.7 |
43 |
Scart 4 input (L) |
3.7 |
44 |
Scart 4 input (R) |
3.7 |
45 |
Analog Shield Ground |
0,0 |
46 |
CINCH - sound input (L) |
3.7 |
47 |
CINCH - sound input (R) |
3.7 |
48 |
Analog Shield Ground |
0,0 |
49 |
Scart 2 sound input (L) |
3.7 |
50 |
Scart 2 sound input (R) |
3.7 |
51 |
Analog Shield Ground |
0,0 |
52 |
Scart sound 1 input (R) |
3.7 |
53 |
Scart 1 sound input (L) |
3.7 |
54 |
A/D converter ref. Voltage |
2.5 |
55 |
Mono sound input |
3.7 |
56 |
Ground for Analog Power Supply Voltage |
0,0 |
57 |
Analog Power Supply Voltage (5V) |
4.9 |
58 |
IF input 1 |
1.5 |
59 |
IF Common reference for IF IN1/IN2 |
1.5 |
60 |
IF input 2 |
0,0 |
61 |
Factory test mode enable (ground) |
0,0 |
62 |
Crystal oss. input |
2.3 |
63 |
Crystal oss. output |
2.3 |
64 |
Not connected (Ground) |
0,0 |
IC317 (TDA 8944J) Audio Output IC
Pin |
Connection |
V DC |
Pin |
Connection |
V DC |
|
|
|
|
|
|
1 |
negative loudspeaker terminal 1 |
6,1 |
10 |
mode select.input (standby,mute,operating) |
0,0 |
|
|
|
|
|
|
2 |
ground channel 1 |
0,0 |
11 |
half supply voltage decoupling (ripple rejection) |
6,2 |
|
|
|
|
|
|
3 |
supply voltage channel 1 |
12,4 |
12 |
positive input 2 |
6,2 |
4 |
positive loudspeaker terminal 1 |
6,1 |
13 |
DC gain control |
0,0 |
5 |
not connected |
0,0 |
14 |
negative loudspeaker terminal 2 |
6,1 |
6 |
positive input 1 |
6,2 |
15 |
ground channel 2 |
0,0 |
7 |
signal ground |
0,0 |
16 |
supply voltage channel 2 |
12,4 |
8 |
negative input 1 |
6,2 |
17 |
positive loudspeaker terminal 2 |
6,2 |
9 |
negative input 2 |
6,2 |
|
|
|
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