Technical description and composition of the PANASONIC TX-LR42FT60 TV, panel type and modules used. The composition of the modules.PANASONIC LED
Model: TX-LR42FT60
Chassis / Version: LA42
Panel: LC420EUD (FF) (F1)
LED backlight: 6916L-1265A, 6920L-0001C
T-CON: 6870C-0450A (FF) (F1)
LED driver (backlight): 6917L-0140A 3PHCC20015A-H
Power Supply (PSU): TNPA5766 TXN / P1XYUE
PWM Power: FA5696N, FA5760N
MOSFET Power: MDF11N60 (B1CERR000085), STD7NM60N (B1CFRR000016)
MainBoard: TNPH1063 1A TXN / A1VWUR
IC MainBoard: AN34043A, 29F4G08
Tuner: J3ACZBC00002 QE261ZC
TX-LR42FT60 Specifications
PANASONIC TX-LR42FT60
General recommendations for TV LCD LED repair
Possible manifestations of defects
- The PANASONIC TX-LR42FT60 TV does not turn on at all. No response to the remote control and front panel control buttons. Indicator lamps do not light up or flash.
Most likely, in this case, the main switching power supply (SMPS) TNPA5766 is faulty. It is necessary to measure its secondary output voltages, and if they are absent, check the power switches (MDF11N60 (B1CERR000085), STD7NM60N (B1CFRR000016)) and rectifier diodes in the converters for a short circuit.
In case of breakdowns of semiconductors in the secondary circuits, the converter can usually work in an emergency in the short-circuit mode, and with a short circuit in the power elements of the primary circuit, the mains fuse often breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements, which can disable it in key mode, or provoke an excess of the maximum current or voltage values. These can be circuits supplying a PWM controller, damper or frequency setting circuits, or OOS (negative feedback) elements in the stabilization circuit. PWM controllers (PWM) FA5696N, FA5760N, in the absence of external damage and short circuit between the terminals, are checked by replacing them with a known good one.
- There is no picture, but there is sound, it reacts to the remote control. Or the image appears when turned on and immediately disappears
Usually, in such cases, a malfunction is detected in the LED panel backlight nodes. 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 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 needs to be replaced.
- The TV does not turn on, the indicator signals the standby or operating mode, or blinks.
Repair or diagnostics of the TNPH1063 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). In cases of complex MB (SSB) repairs and with the necessary skills and equipment, it may sometimes be necessary to replace its AN34043A, 29F4G08 chips and other possible faulty components. Malfunctions associated with the use of BGA soldering technologies are usually easily diagnosed by the warm-up method.
If there is no reception of TV channels, but the TV is working properly from external devices, first of all, you need to check the supply voltage of the J3ACZBC00002 QE261ZC tuner and update the software. I2C communication pulses must be monitored with an oscilloscope.
If the PANASONIC TX-LR42FT60 has no picture, but there is sound, often the LCD backlight LC420EUD (FF) (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 LC420EUD 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 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 TNPH1063 turns out to be faulty; a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, the 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 TNPH1063 with an oscilloscope, as well as synchronizing 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.
Owners of the TX-LR42FT60 TV are advised to contact only qualified specialists with the necessary experience for repair! Attempts to repair yourself without the appropriate knowledge and skills can lead to irreversible negative consequences!
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> PANASONIC TX-LR42FT60 Chassis LA42 for models TX-L42FT60B, TX-LR42FT60
The appearance of the MainBoard TNPH1063 is shown in the figure below:TNPH1063
External view of the power supply
TNPA5766:
TNPA5766
The main features of the PANASONIC TX-LR42FT60 device:
Matrix (LED panel) LC420EUD (FF) (F1) is installed.
Matrix control uses the 6870C-0450A Timing Controller (T-CON).
LED driver 6917L-0140A is used to power the backlight LEDs.
The formation of the necessary supply voltages for all the nodes of the PANASONIC TX-LR42FT60 TV is carried out by the TNPA5766 power module, or its analogs using the FA5696N, FA5760N microcircuits and MDF11N60 (B1CERR000085), STD7NM60N (B1CFRR000016) power switches.
MainBoard - the main board (motherboard) is a TNPH1063 module, using AN34043A, 29F4G08 and others.
Tuner J3ACZBC00002 QE261ZC provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LC420EUD-FFF1
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: IPS, Normally Black, Transmissive
Active Area: 927.94x521.96 mm
Surface: Antiglare (Haze 1%), Hard coating (2H)
Brightness: 400 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 1.06B (8-bit + Dithering), CIE1931 72%
Response Time: 5 (G to G); 8 (MPRT)
Frequency: 120Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (2 ch, 10-bit), 92 pins
Voltage: 12.0V
PANASONIC TX-LR42FT60 TV with LCD LC420EUD, 42 "(107 cm) diagonal in 16: 9 format. The LED panel of this TV is equipped with edge LED backlighting - Edge LED.
There is support for 3D images using passive polarization technology.
The LC420EUD panel and TNPH1063 motherboard firmware provide HD and Full HD viewing at 1920x1080 pixels in 1080p (Full HD) graphics.
The TX-LR42FT60 is equipped with SMART software, built-in applications and the ability to work on the Internet. 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.
The power of the acoustic audio system is 18 W (2x4 + 10 W), provided by 3 speakers. Uses NICAM stereo signal system and Sound Surround function.
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), Wi-Fi, Miracast. A headphone output is provided for individual listening. To connect a computer or laptop, a VGA (D-Sub 15) connector is used, supporting resolutions: 1920x1080.
The digital tuner is capable of receiving terrestrial and cable channels in the DVB-T MPEG4, DVB-C, DVB-T2, DVB-S2 standards.
Dimensions: with stand 956x650x225 mm, without stand 956x564x35 mm.
TV weight: with stand: 16 kg, without stand: 12.5 kg.
Attention! The LC420EUD (FF) (F1) panel of the PANASONIC TX-LR42FT60 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.
