VESTEL MB185 IDTV User manual

MB185 IDTV
SERVICE MANUAL

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Table of Contents
1. INTRODUCTION ........................................................................................................................................................................ 2
SSB LAYOUT.............................................................................................................................................................................. 3
2. T/T2/C/A TUNER (U107)............................................................................................................................................................. 4
3. S/S2 TUNER (U3) OPTIONAL .................................................................................................................................................... 6
4. AUDIO AMPLIFIER STAGES..................................................................................................................................................... 8
A. MAIN AMPLIFIER (U118) (8W/10W/12W options)................................................................................................................ 8
B. SUB-WOOFER AMPLIFIER (U1)........................................................................................................................................... 11
5. POWER STAGE......................................................................................................................................................................... 14
A. FDS4685 8.2A/40V (Q103)................................................................................................................................................. 16
B. DMG8402LDM (Q104)....................................................................................................................................................... 17
C. TPS54528 (U101)............................................................................................................................................................... 18
D. TPS563200 (U102,U105, U106).......................................................................................................................................... 20
E. MP8774GQ-Z 12A QFN16 (U122)....................................................................................................................................... 23
6. MICROCONTROLLER.............................................................................................................................................................. 26
MTK G31 (U108) ......................................................................................................................................................................... 26
7. 8 GB EMMC .............................................................................................................................................................................. 36
SAMSUNG EMMC 8GB KLM8G1GETF-B041 BGA153 (U128)......................................................................................................... 36
8. USB INTERFACE...................................................................................................................................................................... 37
USB POWER SWITCH ADJ SAFE TPS25221 SOT23-6 (U117-U109) ................................................................................................. 37
9. CI INTERFACE ......................................................................................................................................................................... 38
10. SOFTWARE UPDATE............................................................................................................................................................. 39
Main Software Update................................................................................................................................................................ 39
11. TROUBLESHOOTING ............................................................................................................................................................ 39
A. No Backlight Problem ........................................................................................................................................................ 39
B. CI Module Problem............................................................................................................................................................ 41
C. IR Problem ........................................................................................................................................................................ 43
D. Keypad Touchpad Problems............................................................................................................................................... 44
E. USB Problems.................................................................................................................................................................... 44
F. No Sound Problem ............................................................................................................................................................ 45
G. Standby On/Off Problem ................................................................................................................................................... 46
H. No Signal Problem in DVB-S/S2 mode ................................................................................................................................ 46
İ. No Signal Problem in DVB-T mode ..................................................................................................................................... 47
12. SERVICE MENU SETTINGS .................................................................................................................................................. 48
13. GENERAL BLOCK DIAGRAM............................................................................................................................................... 49
IMPORTANT
Before removing the rear cover from the TV for servicing, make sure that no cables are fixated to the cover. Release the
cables from their clamps and disconnect (if any). Failure to do so may damage the wires and/or other components of the
TV.

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1. INTRODUCTION
17MB185 main board is driven by MTK SOC. This IC is a single chip iDTV solution that supports channel
decoding, MPEG decoding, and media-center functionality enabled by a high performance AV CODEC and
CPU.
This board can be driven 50Hz UHD panels.
Key features include:
Combo Front-End Demodulator
A multi standart A/V format decoder
The MACEpro video processor
Home theatre sound processor
Rich internet connectivity and completed digital home network solution
Dual-stream decoder for 3D contents
Multi-purpose CPU for OS and multimedia
Peripheral and power management
Embedded DRAM (for connected option)
Supported peripherals are:
1 RF input VHF I, VHF III, UHF
1 Satellite input
1 Sub-woofer sound socket
3x HDMI inputs (2x side , 1x back side)(with ARC option from 2nd or 3rd input)
1 Common interface(Common)
1 Optic/ Quax S/PDIF output
1 Headphone(Common)
2x USB(2X Side) and 1x internal USB for Wifi/Bluetooth
1 Ethernet-RJ45
1 External Keypad/Tact Switch

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SSB LAYOUT
Power
Con.
MAIN
IC
CI
LAN
LNB
ANT.
HDMI
HP
USB
USB
S/PDIF
Internal
Wifi& BT
Connector
LED
CON
T
C
O
N
B
O
A
R
D
EMMC
Audio
Amp
Speaker
Con.
HDMI
HDMI
Subwoofer
Amp
Subwooferr
Con.

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2. T/T2/C/ATUNER (U107)
Description:
The Si2151 is Silicon Labs' sixth-generation hybrid TV tuner supporting all worldwide terrestrial and cable
TV standards. Requiring no external balun, SAW filters, wirewound inductors or LNAs, the Si2151 offers the
lowest-cost BOM for a hybrid TV tuner. Also included are an integrated power-on reset circuit and an option
for single power supply operation. As with prior-generation Silicon Labs TV tuners, the Si2151 maintains very
high linearity and low noise to deliver superior picture quality and a higher number of received stations when
compared to other silicon tuners. The Si2151 offers increased immunity to WiFi and LTE interference,
eliminating the need for external filtering. For the best performance with next-generation digital TV standards,
such as DVB-T2/C2, the Si2151 delivers industry-leading phase noise performance.
Features:
Worldwide hybrid TV tuner
oAnalog TV: NTSC, PAL/SECAM
oDigital TV: ATSC/QAM, DVBT2/T/C2/C, ISDB-T/C, DTMB
1.7 MHz, 6 MHz, 7 MHz, 8 MHz, and 10 MHz channel bandwidths
42-1002 MHz frequency range
Industry-leading margin to A/74, NorDig, DTG, ARIB, EN55020, OpenCable™,DTMB
Lowest BOM for a hybrid TV tuner
oNo balun, SAW filters, or external inductors required
oIncreased ESD protection on 4pins
Best-in-class real-world reception
oLowest phase noise
oHigh Wi-Fi and LTE immunity
Low power consumption
o3.3 V and 1.8 V power supplies
oIntegrated 1.8 V LDO for 3.3 V singlesupply operation
Integrated power-on reset circuit
Standard CMOS process
3x3 mm, 24-pin QFN package
RoHS compliant
,
Figure 1: Si2151 Pin description

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3. S/S2 TUNER (U3) OPTIONAL
Description
Figure 2: Pin description

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Features
Block Diagram

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4. AUDIOAMPLIFIER STAGES
Figure: The block diagram of the audio part
A. MAIN AMPLIFIER (U118) (8W/10W/12W OPTİONS)
Description
AD82587D is a digital audio amplifier capable of driving a pair of 8 ohm, 20W or a single 4 ohm, 40W
speaker, both which operate with play music at a 24V supply without external heat-sink or fan requirement.
Using I2C digital control interface, the user can control AD82587D’s input format selection, DRC (dynamic
range control), mute and volume control functions. AD82587D has many built-in protection circuits to
safeguard AD82587D from connection errors.
Features
16/18/20/24-bit input with I2S, Left-alignment and Right-alignment data format
PSNR & DR(A-weighting) Loudspeaker: 97dB (PSNR), 105dB (DR) @ 24V
Multiple sampling frequencies (Fs)
32kHz / 44.1kHz / 48kHz and
64kHz / 88.2kHz / 96kHz and
128kHz/176.4kHz/192kHz
System clock = 64x, 128x, 256x, 384x, 512x, 768x,1024x Fs
256x~1024x Fs for 32kHz / 44.1kHz / 48kHz
128x~512x Fs for 64kHz / 88.2kHz / 96kHz
64x~256x Fs for 128kHz /176.4kHz/192kHz
Supply voltage
3.3V for digital circuit

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10V~26V for loudspeaker driver
Loudspeaker output power for Stereo@ 24V
10W x 2ch into 8_ @ 0.16% THD+N
15W x 2ch into 8_ @ 0.18% THD+N
20W x 2ch into 8_ @ 0.24% THD+N
Loudspeaker output power for Mono@ 24V
20W x 1ch into 4_ @ 0.17% THD+N
30W x 1ch into 4_ @ 0.2% THD+N
40W x 1ch into 4_ @ 0.24% THD+N
Sounds processing including:
Volume control (+24dB~-103dB, 0.125dB/step)
Dynamic range control
Power clipping
Channel mixing
User programmed noise gate with hysteresis window
DC-blocking high-pass filter
Anti-pop design
Short circuit and over-temperature protection
I2C control interface with selectable device address
Internal PLL
LV Under-voltage shutdown and HV Under-voltage
detection
Power saving mode
Dynamic temperature control
Figure 3: Pin description

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Figure 4: Functional Block Diagram
Table 1: Absolute Maximum Ratings
Table 2: Recommended Operating Conditions

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B. SUB-WOOFER AMPLIFIER (U1)

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5. POWER STAGE
Figure: Power Block Diagram
Figure: Power Socket and Power Options
Power socket is used for taking 12V_STBY voltage which is produced in power card. Also socket is used for
giving dimming, backlight and standby signals with power card. Power socket pinning is shown in above
figure.
12V_STBY is converted several different voltages on the mainboard which are shown in below figure.

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Figure: Power Block Diagram
List of the components:
SW-1(Q103) → FDS4685 8.2A/40V
SW-2(Q104) → DMG8402LDM 4.2A/30V
DC-DC-1(U101) → TPS54528 ADJ/5A
DC-DC-2(U102) → TPS563201 ADJ/3A
DC-DC-3(U105) → TPS563201 ADJ/3A
DC-DC-4(U106) → TPS563201 ADJ/3A
DC-DC-5(U113) → TPS562201 ADJ/2A
DC-DC-6(U122) → MP8774GQ-Z 12A

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A. FDS4685 8.2A/40V (Q103)
Figure: Pin description

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B. DMG8402LDM (Q104)
Features
Low RDS(ON)
Low Input Capacitance
Fast Switching Speed
Low Input/Output Leakage
Lead Free By Design/RoHS Compliant (Note 1)
Qualified to AEC-Q101 Standards for High Reliability
Pin description

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Electrical Characteristics & Maximum ratings
C. TPS54528 (U101)
General Description
The TPS54528 is an adaptive on-time D-CAP2™mode synchronous buck converter. The TPS54528 enables
system designers to complete the suite of various end-equipment power bus regulators with a cost effective, low
component count, low standby current solution. The main control loop for the TPS54528 uses the D-CAP2™
mode control that provides a fast transient response with no external compensation components. The adaptive
on-time control supports seamless transition between PWM mode at higher load conditions and Eco-mode™
operation at light loads. Eco-mode™ allows the TPS54528 to maintain high efficiency during lighter load
conditions. The TPS54528 also has a proprietary circuit that enables the device to adopt to both low equivalent
series resistance (ESR) output capacitors, such as POSCAP or SP-CAP, and ultra-low ESR ceramic capacitors.
The device operates from 4.5-V to 18-V VIN input. The output voltage can be programmed between 0.76 V
and 6.0 V. The device also features an adjustable soft start time. The TPS54528 is available in the 8-pin DDA
package, and designed to operate from –40°C to 85°C.
Features
D-CAP2™ Mode Enables Fast Transient Response
Low Output Ripple and Allows Ceramic Output Capacitor
Wide VIN Input Voltage Range: 4.5 V to 18 V
Output Voltage Range: 0.76 V to 6.0 V

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Highly Efficient Integrated FETs Optimized for Lower Duty Cycle Applications –65 mΩ (High Side)
and 36 mΩ (Low Side)
High Efficiency, less than 10 μA at shutdown
High Initial Bandgap Reference Accuracy
Adjustable Soft Start
Pre-Biased Soft Start
650-kHz Switching Frequency (fsw)
Cycle By Cycle Over Current Limit
Auto-Skip Eco-mode™ for High Efficiency at Light Load
Pin Assignment