Technical description and composition of the PANASONIC TX-55ASR750 TV, panel type and modules used. The composition of the modules.PANASONIC LED
Model: TX-55ASR750
Chassis / Version: LA51
Panel: LC550DUF (VG) (F1)
LED backlight: 6637L-0034A & 55 V14 Slim DRT Rev0.0 1 R1 / R1 / L1 / L2-type
T-CON: 6870C-0482A
LED driver (backlight): integrated into PSU
PWM LED driver: BD9479FV (C0ZBZ0002164), NJW4840R (C0ZBZ0001936)
MOSFET LED driver: RCX200N20
Power Supply (PSU): TNPA6011
PWM Power: FA5760N (C0DBAYY01329), FA5696N (C0DBBYY00058), NR131S (C0DBAYY01915)
MOSFET Power: B1CBRR000002, B1CERR000096
MainBoard: TNPH1077
IC MainBoard: MN2WS0280, 24C16, AN34043AA, D2837ER
Tuner: TDSA-G370D
Control: WiFi: DNUA-P75, IR: TNPA6010
TX-55ASR750 Specifications
PANASONIC TX-55ASR750
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- PANASONIC TX-55ASR750 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.
Usually, with similar manifestations, the defect is caused by faulty elements in the main TNPA6011 power supply module. It is necessary to make sure that its output voltages are present and, if they are completely absent, check the power switches (B1CBRR000002, B1CERR000096) and rectifier diodes for a possible short circuit.
In case of breakdowns in the secondary circuits of the converter, it can usually work in an emergency mode in a short circuit mode, and with a short circuit in the power elements of the primary circuit, the mains fuse or current sensor in the source of the key is most often cut off.
Mos-Fet power switches used in switching power supplies sometimes fail due to a malfunction of any other elements that can disable it in the key mode, or create an excess of the maximum permissible key parameters. These can be elements supplying a PWM regulator, frequency setting or damper circuits, or elements of negative feedback in the stabilization circuit. PWM controllers FA5760N (C0DBAYY01329), FA5696N (C0DBBYY00058), NR131S (C0DBAYY01915), in the absence of visible damage or outright short circuits between the terminals, are checked by replacing them with new ones, or known to be working properly.
- There is no image, there is sound, it reacts to the remote control. Or the image may appear for a second when turned on and immediately disappear.
The malfunction in most of such cases is found in the nodes and elements of the LED panel backlight. The reason may be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
To check the LED strips for breakage without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter; a voltage of the order of several tens of volts is required.
- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.
Repair or diagnostics of the TNPH1077 motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and the matrix. If necessary, you should update or replace the software (software). When repairing the MB board, you need to check its components MN2WS0280, 24C16, AN34043AA, D2837ER. Defective elements must be replaced. If chips with BGA soldering technology are used, the problem in its implementation is detected by local heating of the chip.
The malfunction of the TDSA-G370D tuner is established after checking the software and all supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be monitored with an oscilloscope.
If the PANASONIC TX-55ASR750 has no picture, but there is sound, often the LCD backlight LC550DUF (VG) (F1) simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.
Replacing the LEDs requires disassembling the LC550DUF LCD panel, a process that requires experience and qualifications from the technician. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels
If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV you can see light through the holes in the panel case.
In this case, the panel may also be faulty - damage to the strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But often the main board MainBoard TNPH1077 turns out to be faulty, a software failure is also possible.
Then, first of all, it is necessary to check the panel supply voltage, fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within normal limits, it is necessary to trace the passage of LVDS signals from the MainBoard TNPH1077 with an oscilloscope, as well as synchronization signals to the loops with drivers.
Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.
We remind users again! Attempts to repair the PANASONIC TX-55ASR750 TV on your own without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> PANASONIC TX-55ASR750 Chassis LA51 for models TX-55AS750E, TX-55ASW754, TX-55ASR750
The MainBoard TNPH1077 is shown in the figure below:TNPH1077
External view of the power supply
The main features of the PANASONIC TX-55ASR750 device:
Installed matrix (LED-panel) LC550DUF (VG) (F1).
Matrix control uses the 6870C-0482A Timing Controller (T-CON).
To power the backlight LEDs, a converter combined with a power supply is used, controlled by the PWM controller BD9479FV (C0ZBZ0002164), NJW4840R (C0ZBZ0001936). RCX200N20 keys are used as power elements of the LED driver.
The formation of the necessary supply voltages for all the nodes of the PANASONIC TX-55ASR750 TV is carried out by the TNPA6011 power module, or its analogs using the FA5760N (C0DBAYY01329), FA5696N (C0DBBYY00058), NR131S (C0DBAYY01915), B1000C0000 BR1000 power switches, type B1000
MainBoard - the main board (motherboard) is a TNPH1077 module, using the MN2WS0280, 24C16, AN34043AA, D2837ER and others.
The TDSA-G370D tuner provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LC550DUF-VGF1
Type: a-Si TFT-LCD, Panel
Diagonal size: 55 inch
Resolution: 1920x1080, FHD
Display Mode: IPS, Normally Black, Transmissive
Active Area: 1209.6x680.4 mm
Surface: Antiglare (Haze 1%), Hard coating (2H)
Brightness: 450 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 16.7M / 1.07B (8-bit / 8-bit + Dithering), CIE1931 72%
Response Time: 5 (G to G); 8 (MPRT)
Frequency: 120Hz
Lamp Type: 6 strings WLED Without Driver
Signal Interface: LVDS (4 ch, 8/10-bit), 92 pins
Voltage: 12.0V
PANASONIC TX-55ASR750 TV with LC550DUF LCD, 55 "(140 cm) diagonal in 16: 9 format. The LCD panel of the TV is equipped with direct backlighting with rear LEDs - Direct LED.
There is support for 3D images using passive polarization technology.
The LC550DUF panel and TNPH1077 motherboard firmware provide HD and Full HD viewing at 1920x1080 pixels in 1080p (Full HD) graphics.
The TX-55ASR750 is equipped with SMART software, built-in applications and Internet connectivity. Internet connection can be made via Wi-Fi wireless connection. The input analog video signal can be processed in PAL, SECAM, NTSC systems. Graphic processing and formation of a digital signal picture occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Multimedia file formats supported by the video processor: MP3, WMA, MPEG4, MKV, JPEG.
Speaker power 20 W (2x10 W) is provided by two speakers. Uses NICAM stereo signal system and Sound Surround function.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, SCART, RGB, HDMI x3, USB x3, Ethernet (RJ-45), Bluetooth, Wi-Fi. A headphone output is provided for individual listening. To connect a computer or laptop, a VGA (D-Sub 15) connector is used that supports resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080, 4096x2160.
The digital tuner is capable of receiving terrestrial and cable channels in the DVB-T MPEG4, DVB-C, DVB-T2, DVB-S2 standards.
Attention! The LC550DUF (VG) (F1) panel of the PANASONIC TX-55ASR750 LED TV is the most expensive element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is 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 unrepairable.