DVB SMP137HDT2 User manual

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DVB-Terrestrial Receiver
SMP137HDT2+SMP012HDT2
Service Manual
This service manual should be used with the User Manual together.
Please read this Service Manual and User Manual carefully before service this product.

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Contents
Safety Instructions ......................................................................................... 3
Generally Guide .................................................................................................................................. 3
Low Potential Leakage Testing ............................................................................................................................... 3
High Potential Leakage Testing .............................................................................................................................. 3
Protect Electro-Static(ES)-sensitivity Device from Electro-Static
Discharge …………………………………………. ………………………………3-4
Electrical Specifications ................................................................................. 5
Mechanical Exploded View Drawing .............................................................. 6
Mechanical Parts List.......................................................................................................................... 7
Packaging and Accessories ........................................................................ 8-9
Packaging Exploded View Drawing .................................................................................................. 10
Appendix 1 Flowchart and Circuit Diagram ...................................................10
Flowchart........................................................................................................................................... 12
Wiring Diagram ............................................................................................................................ 14-15
Circuit Diagram of Decoding Board ............................................................................................. 16-23
Appendix 2 Silkscreen of PCB ......................................................................24
Silkscreen of Decoding Board Top.................................................................................................... 25
Silkscreen of Decoding Board Bottom.............................................................................................. 26
PCB Diagram of Decoding Board Top .............................................................................................. 27
PCB Diagram of Decoding Board Bottom ........................................................................................ 28
Appendix 3 Component List..........................................................................29
Component List of Decoding Board............................................................................................. 30-36

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Safety Instructions
Generally Guide
1. Please check electric circuits before maintenance and change the damaged or over heated components if
short-circuit has been found.
2. Please check all protective devices have been installed well after maintenance, like whether insulation
covering and paper has been installed well or not.
3. In order to avoid electric shock ,please proceed following electrical leakage tests after maintenance.
Low Potential Leakage Testing
Take out power cord from an AC outlet and connect a length of wire between the two leads of the plug.
Use Gear R x 10K of the voltmeter to measure the resistance between shorted-out AC plug and exposed
metallic parts like screw cap, control shaft etc. which shall be infinite.
Picture 1
High Potential Leakage Testing
As shown in Picture 1, connect a resistor of 1.5K, 10W and capacitor of 0.15 uF between exposed metallic
part and well grounded devices (water pipe etc.).
Plug AC power cord directly into the AC socket. Do not use insulated transformer to test.
Use 1000 Ohm/V or more sensitive AC voltmeter to measure AC voltage of the resistor.
Turn over the AC jack and plug into the socket again to iterate the inspection as above.
Inspect the voltage of the resistor between other exposed metallic parts and the earth in the same way.
Any parts’voltage of the resistor should not over 0.75Vrms. A leakage testing machine with voltage over
2,500 V can also be used for this inspection in which case the electric leakage should not be over 0.5mA. When
the leakage exceeds that limit, electric shock may occur. Please check and repair again before hand it over to
users.
4. Protect Electrostatic-Sensitive Devices from Electrostatic Discharge
Some solid states made of semiconductors materials can be easily damaged by commonly static charges,

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those components are usually called electrostatic-sensitive devices. Such like integrated circuits, laser diodes
and field effect devices. The following tips will help you to reduce the impacts on those components while
electrostatic discharging.
1.Please release static which build-up on human body before handling electrostatic-sensitive devices by
using grounded tools. The antistatic strap which can be found in the market will be a good choice.
2.Please install the electrostatic-sensitive devices on conductor products such as aluminum foil to prevent
static build-up after disassembling from this DVT receiver.
3.The soldering iron must be earthed while soldering and unsoldering the electrostatic-sensitive devices.
4.Only antistatic solder can be used for electrostatic-sensitive devices disassembly. The
electrostatic-sensitive devices will be damaged by static without ESD prevention solder while disassembling.
5.Do not use Freon Volatile which may damage the electrostatic-sensitive devices by discharging static.
6.Do not take the new electrostatic-sensitive devices from the antistatic protection package unless you are
ready for installation. (Most electrostatic-sensitive devices will be packed with anti-static foam, foil or similar
conductive materials. And a lead wire to prevent short circuit.)
7.Please contact the core or circuit parts of the device to be installed with ESD protection package before
carry out the new electrostatic-sensitive devices from it. And make sure no power supply on the device and
remember other precautions.
8.Try to reduce body movements while assembling or disassembling electrostatic-sensitive devices. (Clothes
made of fabrics will build-up static by attrition. Feet lifts up from floor will also build-up static.)

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Electrical Specifications
A Audio Section （MPEG-1 Layer Ⅱ, R. L Track Output）
No.
ITEM
UNIT
REQUIREMENTS
Test Environment
1
Audio Output Level
V
1.0～2.0
Output impedance is 10KΩ 1KHz 0dB
2
Frequency Characteristics
dB
+1/-2.0
20Hz-60Hz
0.5
60Hz-17.5KHz
+1/-3
17.5KHz-20KHz
3
S/N
dB
≥70
1KHz 0dB weighting
4
L/R Channel Separation
dB
≥60
N-CBAR100.TS f= 1KHz
P-CBAR75.TS
5
L/R Channel Level Difference
dB
≤0.5
60Hz-18KHz
6
Audio THD
%
≤1
60Hz-18KHz
7
Digital Coaxial Output Level
Vp-p
0.520%
75Ω Load
B Video (MPEG-2MP＠ML)
1
Output range
Video
Vp-p
1.015%
75Ω Load
Brightness/RGB
0.7±10%
Sync
0.308%
2
Frequency Characteristics (75Ω)
dB
0.5
0.5-4.8MHz
dB
≤+0.5/-1.0
4.8-5.0MHz
dB
≤+0.5/-4
5.0-5.5MHz
3
Brightness S/N
dB
≥56
WTD 5MHz
4
Chromatic S/N
dB
AM≥58
Load 75
PM≥51
5
Differential gain（DG）
%
≤5
Load 75
6
Differential phase（DP）
°
≤5
Load 75
7
Brightness non-linear distortion
%
≤5
Load 75
8
△τchrominance-luminance delay inequality
ns
≤30
Load 75
9
△K Chrominance-luminance Gain Inequality
%
≤5
Load 75
10
Brightness Waveform Distortion
%
≤3
Load 75
11
Chrominance Subcarrier Offset is not more than
Hz
200
Load 75
C Demodulation
1
Input Frequency Range
MHz
174~230MHz,470～862MHz (VHF/UHF)
2
Input Level Range
dBm
-75～-20
3
Frequency Offset
MHz
-0.4MHz~+0.74MHz
DPower Supply (~100-240V)
1
+5V
mA
1500
5%
2
+5V Active Antenna Amplifier
mA
30
5V overload protection
E Others
1
Free Fall
Meets QJ/ET08.02-2005 Standards
2
Remote Control Distance
M
≥8
In line
≥6
With range of 30°
3
Rated Power Consumption
W
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Mechanical Exploded View Drawing

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Mechanical Parts List
NO.
Part No.
Part Name
Qty
Notes
1
4110-1842-000H
Face-piece
1
Transparent ABS
2
4111-1842-005H
Bottom Cover
1
ABS
3
2104-1847-300H
Decoding Board
1
4
3211-3008-0016
Screws
ST3x8PTTNi
3
Mainboard/ botton cover

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Packaging and Accessories

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Packaging Exploded View Drawing
Material List
Appendix 1 Flowchart and Circuit Diagram
Flowchart
Wiring Diagram
Circuit Diagram of Decoding Board
NO.
Material No.
Name
Qty
1
4401-1656-000H
White Box
1
2
User Manual
1
3
2301-1555-000H
Remote Control
1
4
4413-1812-1100
Bubble Bag 180*210mm
1

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