Friday 7 August 2020

REPAIRING / SERVICING TV POLARLINE 43PL51TC-SM

Technical description and composition of the POLARLINE 43PL51TC-SM TV, panel type and modules used. The composition of the modules.
POLARLINE LED
Model: 43PL51TC-SM
Chassis / Version: TP.MT5510S.PB802
Panel: LC430DUY-SHA1 D00
LED backlight: NPB12D770103BL041-001H CY-42-4X10-0427
T-CON: 6870C-0532A 43 6871L
LED driver (backlight): integrated into MainBoard
PWM LED driver: 560mA
Power Supply (PSU): integrated into MainBoard
MainBoard: TP.MT5510S.PB802
IC MainBoard: MT5659QHNT, KLM8G1GEFT-B041
Tuner: NoName
Specifications 43PL51TC-SM
POLARLINE 43PL51TC-SM
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- POLARLINE 43PL51TC-SM does not turn on and does not show any signs of operability at all. Does not blink indicators and does not respond to control buttons.
In this case, first of all, you should check the operability of the main power source - the AC / DC mains voltage converter, all of which are located on the MainBoard TP.MT5510S.PB802. It is necessary to measure its output supply voltages, and if they are absent, check the serviceability of the power switches of the converters and rectifier diodes for the probability of breakdown in semiconductor PN junctions.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in an emergency mode of short circuit without output voltages, and with a short circuit in the elements of the primary circuit, the mains fuse most often breaks off immediately and less often the current sensor in the source of the key.
Breakdown of Mos-Fet switches used in switching power supplies is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM regulator, in frequency-setting or damper circuits, as well as in negative feedback stabilization. PWM microcircuits (PWM) are usually checked by replacing them with new ones, or knowingly working.
- There is no picture, there is sound, it reacts to the remote control, the channels are switched. In some cases, the image appears when turned on and disappears immediately.
In such cases, the most likely malfunction of the LED panel backlighting elements. The reason may be in the breakage of the LEDs, in the stabilization of their power supply, or in the violation of the contact connections of the strings connectors,
To test the LED strips, in order to open all the transitions of the LEDs, several tens of volts or more are needed; it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED junctions in forward bias, you can sometimes detect the presence of a protective zener diode PN junction by connecting the probes in the opposite direction. If the zener diode is cut off or broken in K / Z, then the LED is faulty and requires replacement.
- The indicator blinks or is on constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the TP.MT5510S.PB802 motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Complex repair of MB (SSB) is possible only in a service center with the necessary equipment. Checking or replacing elements MT5659QHNT, KLM8G1GEFT-B041 requires the necessary training and professional skills to repair modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by the warm-up method.
If you suspect a malfunction of the NoName tuner, first of all, you need to make sure that the software is correct, as well as the presence of the necessary levels of supply voltages and pulses of data exchange with the processor via the I2C bus on the corresponding terminals of the tuner.
Once again, we remind TV users: do not attempt to repair yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repair to professionals with sufficient experience in the field of electronic repair.
The main features of the POLARLINE 43PL51TC-SM device:
Installed matrix (LED panel) LC430DUY-SHA1 D00.
Matrix control uses the 6870C-0532A Timing Controller (T-CON).
To power the backlight LEDs, a converter combined with the TP.MT5510S.PB802 main board is used, controlled by a 560mA PWM controller.
The power module is combined with the MainBoard and is made according to the AC / DC flyback converter circuit.
MainBoard - the main board (motherboard) is a TP.MT5510S.PB802 module, using MT5659QHNT, KLM8G1GEFT-B041 and others.
Tuner NoName provides reception of television programs and tuning to channels.


POLARLINE 43PL51TC-SM TV with LCD LC430DUY-SHA1, 43 "(109 cm) diagonal 16: 9. The required screen brightness of 290 cd / m2 is provided by LED backlighting. Contrast, as the ratio of maximum brightness to minimum, is 1200: 1. The LCD panel of the TV is equipped with direct backlighting with LEDs - Direct LED.
There is a convenient function for recording TV programs on a USB-drive with subsequent viewing at another time (TimeShift).
The design and technical capabilities of the TV provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphic resolution at 1080p (Full HD).
43PL51TC-SM TV has built-in SMART software and preinstalled Android Operating System. Internet connection can be made via Wi-Fi wireless connection. Supported media file formats: MP3, MPEG4, HEVC (H.265), Xvid, MKV, JPEG.
Speaker power 14 W (2x7 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, VGA, HDMI 1.4 x3, USB x2, Ethernet (RJ-45), Wi-Fi 802.11n. A headphone output is provided.
The digital tuner is capable of receiving TV channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Dimensions: with stand 967x597x180 mm, without stand 967x569x89 mm.
TV weight: 7 kg.
Attention! The LC430DUY-SHA1 D00 panel of the POLARLINE 43PL51TC-SM LED TV is an expensive and unreliable element.
Do not allow any impacts on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV non-repairable.