Technical description and composition of the PANASONIC TX-40DR400 TV, panel type and modules used. The composition of the modules.PANASONIC LED
Model: TX-40DR400
Chassis / Version: LA66
Panel: V400HJ9-MD1
LED driver (backlight): integrated into PSU
PWM LED driver: BD9289F-HVGE2
MOSFET LED driver: B1CFRL000042
Power Supply (PSU): TNPA6247 1 P
PWM Power: NCP1234AD
MOSFET Power: TK8A65D (B1CERR000067)
MainBoard: TNPH1155 2 A
IC MainBoard: CPU: MN2WS0270PB (Peaks-sLD8), AUDIO: C1AB00003984
Tuner: C1AB00004028 DVB-T2 / T / C DEMODULATOR
Control: IR: TNPA6056
TX-40DR400 Specifications
PANASONIC TX-40DR400
General recommendations for TV LCD LED repair
Possible malfunctions
- The PANASONIC TX-40DR400 TV does not turn on, does not respond to the remote control and control panel buttons, the indicators do not light up or flash.
In some cases, the TNPA6247 power supply module is faulty with similar manifestations. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches (TK8A65D (B1CERR000067)) and rectifier diodes for possible partial or complete breakdown.
In case of breakdowns in the secondary circuits, the converter, as a rule, can operate in an emergency in the short-circuit mode, and in case of a short circuit in the power elements of the primary circuit, the mains fuse is usually cut off.
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 the PWM controller, in frequency setting or damper circuits, as well as in negative feedback stabilization. PWM microcircuits (PWM) NCP1234AD are usually checked by replacing them with new ones, or knowingly working.
- 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 disappear immediately.
Often in such cases, there is no backlighting of the LED panel. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
It should be remembered that it is not possible to determine an open circuit in the LED lines without disassembling the panels using a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then you need to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow opening the LED in the forward direction or dual LEds are used, then the PN transition of the emergency zener diode can indirectly serve as an indicator of serviceability. In the event of a malfunction of the LED-a, the PN-junction of the Zener diode will either be cut off, or broken through in the SC.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals the standby mode.
If the PANASONIC TX-40DR400 has no image, but there is sound, the display backlight often 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 LCD panel - a process that requires experience and qualifications from the master. 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 the 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 turns out to be faulty, a software failure is also possible.
Then, first of all, it is necessary 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 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 cables and panel strips.
Repair or diagnostics of the TNPH1155 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 an MB board, you need to check its components CPU: MN2WS0270PB (Peaks-sLD8), AUDIO: C1AB00003984. Defective elements should be replaced. If chips with BGA soldering technology are used, the problem in its implementation is detected by local heating of the chip.
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 C1AB00004028 DVB-T2 / T / C DEMODULATOR tuner and update the software. I2C communication pulses must be monitored with an oscilloscope.
Users and owners of TVs should remember that attempts to self-repair the PANASONIC TX-40DR400 TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> PANASONIC TX-40DR400 Chassis LA66
The MainBoard TNPH1155 is shown in the figure below:TNPH1155
External view of the power supply
Main features of the PANASONIC TX-40DR400 device:
Installed matrix (LED panel) V400HJ9-MD1.
To power the backlight LEDs, a converter combined with a power supply is used, controlled by a BD9289F-HVGE2 PWM controller. The keys of the B1CFRL000042 type are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the PANASONIC TX-40DR400 TV is carried out by the TNPA6247 power module, or its analogs using NCP1234AD microcircuits and TK8A65D power switches (B1CERR000067).
MainBoard - the main board (motherboard) is a TNPH1155 module, using CPU chips: MN2WS0270PB (Peaks-sLD8), AUDIO: C1AB00003984 and others.
Tuner C1AB00004028 DVB-T2 / T / C DEMODULATOR provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: INNOLUX
Model: V400HJ9-MD1
Type: a-Si TFT-LCD, Panel
Diagonal size: 40 inch
Resolution: 1920x1080, FHD
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 878.112x485.352 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Brightness: 300 cd / m²
Contrast Ratio: 5000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 9.5 (G to G)
Frequency: 60Hz
Lamp Type: WLED Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V .......
If the TV malfunctions during operation, you should not forget about the manufacturer's (seller's) warranty obligations, which are indicated in the accompanying documents.
If the PANASONIC TX-40DR400 does not turn on or turns off, it is sometimes useful to check the sockets and extension cords where the TV is connected to the network.
If the PANASONIC TX-40DR400 does not respond to commands from the remote control, but the control buttons on the panel work, there is a high probability of a remote control malfunction (the remote control does not work). It is advisable to check or replace the batteries in it.
If, while watching terrestrial or cable programs, you receive a no-signal (no signal) alert, check the antenna or cable connection.
You can make sure the TV is working from other external signal sources.
If there is no sound when watching analogue TV programs, you should check the sound system for Russia D / K (6.5 MHz), for Europe B / G (5.5 MHz) in the settings. In modern TVs for setting color and sound standards, the region is usually chosen - for "East Europe" (Eastern Europe).
If PANASONIC TX-40DR400 freezes, does not respond to the remote control and control panel buttons, sometimes Reset can help - rebooting the processor. To do this, you must disconnect the TV from the network by pulling out the power plug from the outlet, and turn it back on after 15-20 seconds.
TV PANASONIC TX-40DR400 with LCD display, diagonal size 40 "(102 cm) 16: 9 format. The technology of manufacturing the screen of this TV model is realized with LED backlighting.
The panel and motherboard firmware provide HD and Full HD viewing at 1920x1080 pixels in 1080p (Full HD) graphics. Multimedia file formats supported by the video processor: MP3, WMA, MPEG4, MKV, JPEG.
The power of the acoustic audio system is 20 W (2x10 W) provided by two speakers. NICAM STEREO sound processing system is used.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, SCART, HDMI x2, USB. A headphone output is provided for individual listening.
The digital tuner is capable of receiving terrestrial and cable channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Dimensions: with stand 902x569x238 mm, without stand 902x522x88 mm.
TV weight: with stand: 8.5 kg, without stand: 8 kg.
Attention! The panel of the PANASONIC TX-40DR400 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.
