Technical description and composition of the PANASONIC TX-43DR300ZZ TV, panel type and modules used. The composition of the modules.PANASONIC LED
Model: TX-43DR300ZZ
Chassis / Version: MSD3463-T8C1
Panel: K430WD9-LA260A4
LED backlight: K420WD7 4708-K420WD-A3213K01
T-CON: 6870C-0532A
LED driver (backlight): integrated into PSU
PWM LED driver: MP3394S
MOSFET LED driver: AOD256
Power Supply (PSU): integrated into MainBoard
PWM Power: OB5269CP
MOSFET Power: 10N65
MainBoard: MSD3463-T8C1
IC MainBoard: CPU: MSD3463-GSA, SPI FLASH: MX25L6406, AUDIO: TPA3110D2
Tuner: SI2151
Control: IR: 9015-112L73-61031131
TX-43DR300ZZ Specifications
PANASONIC TX-43DR300ZZ
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- PANASONIC TX-43DR300ZZ does not turn on, the indicators on the front panel do not light up or flash. The TV does not respond to the control buttons and the remote control.
In such cases, the common power supply is often faulty - the AC / DC converter of the mains voltage, which is combined with the elements of the MSD3463-T8C1 main board. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, the serviceability of the power switches (10N65) and rectifier diodes should be checked for a possible breakdown (short circuit).
In case of breakdowns in the secondary circuits, the converter can operate in short-circuit mode, and in case of short-circuit in the elements of the primary circuit, the mains fuse usually breaks off.
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 the PWM controller, damper or frequency setting circuits, or OOS (negative feedback) elements in the stabilization circuit. PWM controllers (PWM) OB5269CP, 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 and reaction to commands from the remote control. Or the image appears immediately after switching on and disappears.
A malfunction is usually in these cases most likely in the backlight units of the display matrix. 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.
It is impossible to check the LED bars for a break without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts is required, and ideally a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters tend to light one 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as an indicator of serviceability. In faulty LEDs, the zener diode will either be cut off, or pierced in the K / Z.
- 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 MSD3463-T8C1 motherboard should begin with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Complicated repair of MB (SSB) board is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the CPU elements: MSD3463-GSA, SPI FLASH: MX25L6406, AUDIO: TPA3110D2. Malfunctions in BGA chips are usually easy to detect by warm-up.
If you suspect a malfunction of the SI2151 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 outputs of the tuner.
If the PANASONIC TX-43DR300ZZ has no image, but there is sound, the display backlight K430WD9-LA260A4 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 K430WD9-LA260A4 - 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 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 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 the main board MainBoard MSD3463-T8C1 often 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 MSD3463-T8C1 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 cables and panel strips.
Owners of the TX-43DR300ZZ 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-43DR300ZZ Chassis MSD3463-T8C1 for TX-32DR300ZZ, TX-43DR300ZZ
To reduce the backlight current in LED drivers with an MP3394S (MP3394) controller, increase the resistance of the resistor from pin 6 (ISET) to the case. The maximum current in each channel (in milliamperes) for the resistor Rset (in kilo-ohms) is determined from the ratio 790 * 1.23V / (Rset + 0.4).
TV LED IC MP3394/MPS3394S LED Driver Diagnostics Throubleshooting
The earlier MP3394 was replaced by MPS3394S, which is an upgraded version of the same IC, and found in the 17IPS20 power supply board. It is the main heart of the backlighting LED drive and the failure of this IC can cause the TV not to start. This is a voltage step-up IC that takes 5-V to 28-V at its input pin 15 (Vin) and raises it to drive four independent strings of LEDs. It also performs other functions such as voltage regulation between the LED strings, and provides a dimming facility using pulse-width modulation (PWM). An important aspect of this IC is that it has built-in open and short LED protection circuitry. It is also able to sense the current and voltage of the LED matrix load and determine abnormal conditions. That means that if all the LEDs in the matrix go open or short, it will prevent the television from switching ON.
The IC has internal control logic that produces the GATE signal to drive an external MOSFET transistor. This is the transistor that is switched against an inductor to step-up the voltage, and the gate signal is produced only when the internal control logic detects normal conditions. It is able to determine normal/abnormal conditions through internal comparators, and one such is the LED Over-Voltage Protection (LED OVP) comparator that provides Short String Protection (SSP).
When the TV is switched ON, this IC is enabled through pin 2, by a voltage greater than 1.8-V. It first checks the circuit configuration, and then checks the over-voltage protection signal at (pin 12) to determine if the rectifier diode is open and whether the booster MOSFET (driven by the GATE signal) is short to ground. If the OVP voltage at pin 12 is lower than 70-mV (may be different for other board versions), then it disables itself and the TV will not start.
On the 17IPS20 board, the GATE signal is known as GATE_LED, which drives a bi-polar junction transistor (BJT) Q500 (BC858B). This transistor then drives Q502/Q503 MOSFET booster group of transistors to step-up the voltage (shown in the following pages of this article). In this circuit configuration the inductance coils are L500 and L501. The high voltage produced then goes into a group of rectifier diodes D503 and D504 producing a positive DC voltage for the LEDs. The over voltage protection signal is known as OVP_LED. Whilst all the LED strings take their power from this positive voltage source, they all have separate independent drain pins through the MPS3394S controller IC.
There are also other parameters to consider such as Under-Voltage Lock-Out (UVLO), which is determined by measuring the rising-edge of Vin. This parameter has to be between 3.5-V and 4.4-V, with 3.9-V being the typical value. It is a very clever IC as it can also detect open and short LED strings in the backlight array.
Although this diagnostic cannot tell you the condition of each individual diode, it can indicate the condition of each string of diodes in the backlight matrix. The MPS3394S IC (SOIC16 package) drives four separate strings of LEDs through dedicated open drain output pins. LED string 1 is driven by pin 11, LED string 2 by pin 10, LED string 3 by pin 9, and LED string 4 by pin 8. It also monitors the voltages at these pins so that if there was a shorted LED in one of the strings then it would disconnect that string. If the voltage at any of these pins is greater than 6.1-V, then this condition triggers the short circuit protection mechanism for disconnecting the string at that pin. It is also possible to determine an open string, and in this case, this condition is detected when the pin voltage is lower than 196-mV.
Interestingly, this IC is designed such that it will always try to light at least one string if it is working. The only time when the step-up converter shuts-down completely is if all the strings were either open, or short. Therefore, before you rush off to eBay to buy a new chip, measure the voltages at these pins to make sure that the diodes are not faulty. Otherwise, you will end up wasting a lot of time and money!
Additional MainBoard RepairThe appearance of the MainBoard MSD3463-T8C1 is shown in the figure below:
MSD3463-T8C1
MSD3463-T8C1 can be used in TVs:
PHILIPS 32PHT4001/60 (Panel K320WD92), PHILIPS 43PFT4001/60 (Panel K430WD9), TELEFUNKEN TF-LED39S35T2 (Panel K390WD5 K390WD5UB280H200), TELEFUNKEN TF-LED32S35T2 (Panel K320WD5).
Main features of the PANASONIC TX-43DR300ZZ device:
Installed matrix (LED panel) K430WD9-LA260A4.
Matrix control uses the 6870C-0532A Timing Controller (T-CON).
A converter combined with a power supply is used to power the backlight LEDs, and is controlled by the MP3394S PWM controller. The keys of the AOD256 type are used as power elements of the LED driver.
The power module is combined with the MainBoard and is made according to the AC / DC flyback voltage converter using OB5269CP microcircuits and 10N65 power switches.
MainBoard - the main board (motherboard) is an MSD3463-T8C1 module, using CPU chips: MSD3463-GSA, SPI FLASH: MX25L6406, AUDIO: TPA3110D2 and others.
The SI2151 tuner provides reception of television programs and tuning to channels.
TV PANASONIC TX-43DR300ZZ with LCD K430WD9-LA260A4, diagonal size 43 "(109 cm) 16: 9 format. The technology of manufacturing the screen of this TV model is realized with LED backlighting.
K430WD9-LA260A4 panel and MSD3463-T8C1 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, VGA, HDMI x3, USB x2. 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 969x620x222 mm, without stand 969x567x78 mm.
Attention! Panel K430WD9-LA260A4 LED TV PANASONIC TX-43DR300ZZ 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.
