Technical description and composition of the PANASONIC TX-LR42ET60 TV, panel type and modules used. The composition of the modules.PANASONIC LED
Model: TX-LR42ET60
Chassis / Version: LA41
Panel: LC420EUD (FF) (F1)
LED backlight: 6922L-0077 V9F413 GE 6916L1265A
T-CON: 6870C-0450A (FF) (F1)
LED driver (backlight): 6917L-0140A 3PHCC20015A-H PCLF-206 A REV0.61
Power Supply (PSU): TNPA5766 1 P TXN / P1YDUEZ
PWM Power: FA5696N, FA5760N
MOSFET Power: MDF11N60 (B1CERR000085), STD7NM60N (B1CFRR000016)
MainBoard: TNPH1038
IC MainBoard: CPU: MT5590PAHJ
Tuner: TDSA-G270D
TX-LR42ET60 Specifications
PANASONIC TX-LR42ET60
General recommendations for TV LCD LED repair
Possible malfunctions
- TV PANASONIC TX-LR42ET60 does not turn on and does not show any signs of turning on, does not respond to control buttons and to the remote control.
In such cases, you should start looking for a fault in the circuits of the TNPA5766 power supply. It is necessary to measure its output voltages, and if they are absent (full or partial), the serviceability of the power switches (MDF11N60 (B1CERR000085), STD7NM60N (B1CFRR000016)) of the converters and rectifier diodes should be checked for a possible short circuit.
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 power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM) FA5696N, FA5760N, if they do not have visible damage to the case and an open short circuit between the terminals, are usually checked by replacing.
- There is no image, there is sound, it reacts to the remote control. Or, immediately after switching on for a second, the image may appear and immediately disappear.
In some of these cases, the malfunction is caused by the lack of display backlighting. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
When trying to detect a break in the LED lines, it should be borne in mind that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
- The TV does not go into operation, does not respond to the remote control. The indicator on the front panel is on or blinking.
Repair or diagnostics of the TNPH1038 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 some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - CPU: MT5590PAHJ with new or known good ones. In cases where BGA technologies are used, defects are usually localized by heating.
Before changing the DVB-T / T2 / C tuner, if it is not possible to tune to TV channels, you should make sure that there are supply voltages, which must be measured at the corresponding tuner terminals and check the software for correctness. The pulses of data exchange between the tuner and the processor can be monitored with an oscilloscope
If the PANASONIC TX-LR42ET60 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 panelsIf 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 the main board MainBoard TNPH1038 often 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 the normal range, it is necessary to trace the passage of LVDS signals from the MainBoard TNPH1038 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 self-repair the PANASONIC TX-LR42ET60 TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> PANASONIC TX-LR42ET60 Chassis LA41 for models TX-L42ET60B, TX-L42ET60Y, TX-LR42ET60
The MainBoard TNPH1038 is shown in the figure below:
TNPH1038
External view of the power supply
The main features of the PANASONIC TX-LR42ET60 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 nodes of the PANASONIC TX-LR42ET60 TV is carried out by the TNPA5766 power module, or its analogs using FA5696N, FA5760N microcircuits and MDF11N60 (B1CERR000085), STD7NM60N (B1CFRR000016) power switches.
MainBoard - the main board (motherboard) is a TNPH1038 module, using CPU chips: MT5590PAHJ and others.
The TDSA-G270D tuner 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
TV PANASONIC TX-LR42ET60 with LCD LC420EUD, diagonal size 42 "(107 cm) 16: 9 format. The technology of manufacturing the screen of this TV model is realized with LED backlighting.
There is support for 3D images using passive polarization technology.
The LC420EUD panel and TNPH1038 motherboard firmware provide HD and Full HD viewing at 1920x1080 pixels in 1080p (Full HD) graphics.
The TX-LR42ET60 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.
An external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, SCART, RGB, HDMI x3, USB x2, Ethernet (RJ-45), Wi-Fi. 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 standards.
Dimensions: with stand 956x620x227 mm, without stand 956x564x35 mm.
TV weight: with stand: 14.5 kg, without stand: 12.5 kg.
Attention! The LC420EUD (FF) (F1) panel of the PANASONIC TX-LR42ET60 LED TV is the most expensive item.
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.
