Thursday 30 January 2020

How to enter the service mode - Vestel 17MB230 IDTV – used in Vestel, Regal, Finlux, Telefunken and many other brand LCD TVs


17MB230 main board is driven by Novatek SOC. This IC is a single chip iDTV solution which compliants with variety ATV as NTSC, PAL and SECAM, and DTV standards as ISDB-T, DVB-T/-T2/-C/-S/-S2/-S2X, ITU-T J.83B, 8VSB, DTMB, integrates DTV and multi-media AV decoder, SIF demodulator, and support A/V post-processing
SERVICE MENU SETTINGS
In order to reach service menu, first Press “MENU” button, then write “4725” by using remote controller.  
You can see the service menu main screen. 
You can check SW releases by using this menu. In addition, you can make changes on video, audio etc. by using video settings, audio settings titles.
T/T2/C/A TUNER (U1)
The MxL661 is a highly integrated low-power silicon tuner IC that targets all global and digital cable standards. Broadband input filtering and channel filtering have been completely integrated on-chip. This integration enables a compact design resulting in small footprint, low Bill-Of-Material (BOM) cost, and low-power consumption.
A signal at the 75ohm RF input is filtered and converted to a programmable IF output frequency. Automatic Gain Control (AGC), LO generation, and channel selectivity functions are completey integrated on the chip. All functions of the IC can be controlled using the I2C interface.  The MxL is available in a 4 mm x 4mm x 0.85mm3, 24-pin QFN package.
• Tuning range from 44MHz to 1002MHz
• Programmable channel bandwidths of 6, 7, and 8MHz
• Integrated channel filtering
• Low power consumption with 3.3V and 1.8V dual-supply operation - 351 MW (digital terrestrial)
• On-chip voltage regulator enables single supply 3.3V operation
• Programmable IF frequency and IF spectrum inversion
• Programmable RF to IF delay for ATV scrambling systems that relies on the H-Sync method
• Optional balun-less application note for cost-sensitive applications
• Reference clock output available for re-use by demodulators and additional tuners in multi-channel applications
• Input power reporting
• Open-drain General Purpose Output GPO available for controlling off-chip circuitry
• I2C compatible digital control interface
• RoHS compliance.
S/S2 TUNER (U142)
The AV2018 is a highly integrated silicon tuner for DVB-S2 standard. It integrates a synthesizer, crystal oscillator, LDO, loop through path, and a direct conversion receiver including LNA, RF variable gain amplifiers, Mixer, programmable channel filter, and PGA.  The low noise figure of the receiver and loop through path eliminates the need of an external LNA. The integrated crystal oscillator can provide a reference clock for demodulator. The LDO supplies all the internal blocks the only an external voltage source is required. The AV2018 requires only a small number of external components, thus enables very competitive design.  The AV2018 implements an automatic gain control mechanism that only an analog control signal from the demodulator is required to from a close-loop gain control. The mechanism will arrange the gain of the receiver blocks to achieve best performance according to the control signal voltage. The embedded automatic calibration mechanism provides precise control of channel filter bandwidth and DC offset, no additional calibration procedure is required.
• Input RF Frequency: 950Mhz to 2150Mhz
• Single +3.3V power Supply
• Embedded LNA, Mixer, VCO, crystal oscillator, and LDO
• Low Noise Figure: 5 dB, typical
• Embedded DC offset Cancellation Circuit
• Programmable channel filter with bandwith from 4MHz to 40MHz
• Automatic gain control
• Embedded RF signal loop through path
• Single-ended I/Q interface
• QFN3*3mm 16pin package.
MAIN AMPLIFIER (U9)(6-8-10 W OPTION)
AD82587D is a digital audio amplifier capable of driving a pair of 8 ohm, 20W or a single 4ohm, 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, mute and volume control functions. AD82587D has many built-in protection circuits to safeguard AD82587D from connection errors.
• 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
 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.
SUBWOOFER AMPLIFIER (U8) (12 W)
AD82586C is a digital audio amplifier capable of driving a pair of 8 ohm, 20W operating at 24V supply without external heat-sink or fan requirement with play music.  AD82586C has 20 bands EQ function and can operate 20W stereo or 40W mono optionally.
AD82586C can provide advanced audio processing capabilities, such as volume control, 20 bands speaker EQ, audio mixing, 3D surround and DRC (dynamic range control). These functions are fully programmable via a simple I2C control interface.
Robust protection circuits are provided to protect AD82586C from damage due to accidental erroneous operating condition. AD82586C is more tolerant to noise and PVT (Process, Voltage, and Temperature) variation than the analog Class-AB or Class-D audio amplifier counterpart implemented by analog circuit design. AD82586C is pop free during instantaneous power switch because of its built-in, robust anti-pop circuit.
• 16/18/20/24-bits input with I2S, Left-alignment and Right-alignment data format.
• PSNR & DR (A-weighting) Loudspeaker: 99dB (PSNR), 104dB (DR) @24V. Up
• Multiple sampling frequencies (Fs)
32kHz / 44.1kHz / 48kHz and
64kHz / 88.2kHz / 96kHz and
128kHz / 176.4kHz / 192kHz
• System clock = 64x, 128x, 192x, 256x, 384x, 512x, 576x, 768x, 1024x Fs
64x~1024x Fs for 32kHz / 44.1kHz / 48kHz
64x~512x Fs for 64kHz / 88.2kHz / 96kHz
64x~256x Fs for 128kHz / 176.4kHz / 192kHz
• Supply voltage
3.3V for digital circuit
10V~26V for loudspeaker driver
• Loudspeaker output power at 24V
10W x 2CH into 8 ohm @0.17% THD+N for stereo
20W x 2CH into 8 ohm @0.26% THD+N for stereo
• Sound processing including:
20 bands parametric speaker EQ
Volume control (+24dB~-103dB, 0.125dB/step)
Dynamic Range Control (DRC)
Dual band DRC
Power clipping
3D surround sound
Channel mixing
Noise gate with hysteresis window
Bass/Treble tone control
DC-blocking high-pass filter
• Anti-pop design
• Short circuit and over-temperature protection
• I2C control interface with selectable device address
• Support hardware and software reset
• Internal PLL
• LV Under-Voltage shutdown and HV Under-Voltage detection
• Power saving mode.
HEADPHONE AMPLIFIER (U5)
The AD22657B is a 2-Vrms cap-less stereo line driver. The device is ideal for single supply electronics.  Cap-less design can eliminate output dc-blocking capacitors for better low frequency response and save cost.
The AD22657B is capable of delivering 2-Vrms output into a 10k ohm load with 3.3V supply. The gain settings can be set by users from 1V/V to 10V/V externally. The AD22657B has under voltage protection to prevent POP noise. Build-in shutdown control and de-pop control sequence also help AD22657B to be a pop-less device. The AD22657B is available in a 10-pin MSOP package.
POWER STAGE
Power socket is used for taking voltages which are 12V_stby and 24V (VDD_Audio for 10W option via power_pin1). These voltages are produced in power card. Also socket is used for giving dimming, back-light and stand-by signals with power card.
C1 Module connector details and problems
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.
The MP8774 is a fully integrated high-frequency, synchronous, rectified, step-down, switch-mode converter with internal power MOSFETs. The MP8874 offers a very compact solution that achieves 12A of continuous output current with excellent load and line regulation over a wide input range. The MP8774 uses synchronous mode operation for higher efficiency over the output current load range. Constant-on-time (COT) control operation provides very fast transient response, easy loop design, and very tight output regulation. Full protection features include short-circuit protection (SCP), over-current protection (OCP), under-voltage protection (UVP), and thermal shutdown. The MP8774 requires a minimal number of readily available, standard, external components and is available in a space-saving QFN-16 (3mmx3mm) package.
The APL5910 is a 1A ultra low dropout linear regulator. The IC needs two supply voltages, one is a control voltage (VCNTL) for the control circuitry, the other is a main supply voltage (VIN) for power conversion, to reduce power dissipation and provide extremely low dropout voltage. The APL5910 integrates many functions.
A Power-On- Reset (POR) circuit monitors both supply voltages on VCNTL and VIN pins to prevent erroneous operations. The functions of thermal shutdown and current-limit protect the device against thermal and current over-loads. A POK indicates that the output voltage status with a delay time set internally. It can control other converter for power sequence. The APL5910 can be enabled by other power systems. Pulling and holding the EN voltage below 0.4V shuts off the output.
The APL5910 is available in a SOP-8P package which features small size as SOP-8 and an Exposed Pad to reduce the junction-to-case resistance to extend power range of applications.
NOVATEK NT72671TBG MICROCONTROLLER
NT72671TBG is an integrated digital TV system-on-chip which complaints with variety ATV standards (NTSC, PAL and SECAM), and DTV standards (ISDB-T, DVB-T/-T2/-C/-S/-S2/-S2X, ITU-TJ.83B, 8VSB, and DTMB), and integrates DTV and multi-media AV decoder, SIF demodulator, and support A/V post-processing. The integrated video ADC and video decoder support PC VGA port, YPbPr or SCART, CVBS and SCART S-Video Input. The video decoder supports universal TV video format. The integrated audio ADC
supports stereo audio input corresponding to video input sources. The integrated TV sound decoder supports universal TV sound format. The advanced picture quality and color engine create more vivid image impression than ever. The HDMI receiver v2.0 supports deep color, CEC features and 3D input formats. The USB high speed host supports updating firmware code, multi-media playback from the external USB flash devices.
The standby controller can operate solely from the main system, powered by the standby power-source from power module, consumes as low current as possible. It meets the requirement of Green appliance.