Technical description and composition of the PANASONIC TX-LR50B6 TV, panel type and modules used. The composition of the modules.PANASONIC LED
Model: TX-LR50B6
Chassis / Version: KM21E
Panel: LC500DUE-SFR1
LED backlight: 6916L-1276A, 6916L-1272A, 6916L-1273A, 6916L-1241A
T-CON: 6870C-0452A
LED driver (backlight): TNP4G549
PWM LED driver: BL0200C (C1ZBZ0004953)
MOSFET LED driver: B1CFRM000028, B1CFML000007
Power Supply (PSU): TNPA5807 2 P
PWM Power: FA5696N, FA5760N, LV5980MC
MOSFET Power: STD7NM60N, STD7NM60N
MainBoard: TNP4G548 1 A
IC MainBoard: Peaks-sLD8, MT29F1G08ABAEAH, K4B1G1646G-BCK0
Tuner: TDSA-G220D (J3ACAAC00008)
TX-LR50B6 Specifications
PANASONIC TX-LR50B6
General recommendations for TV LCD LED repair
Possible malfunctions
- The PANASONIC TX-LR50B6 TV does not turn on and does not show any signs of operation at all. No response to the remote control and front panel control buttons.
Usually, with such manifestations, the defect is caused by faulty elements in the main TNPA5807 power supply module. It is necessary to measure its secondary output voltages, and if they are absent, check the power switches (STD7NM60N, STD7NM60N) and rectifier diodes in the converters for a 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 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, LV5980MC, 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 disappears immediately
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.
It is impossible to check the line of series-connected LEDs without a special current source, and it is unsafe for them to use any voltage sources above 12V for this purpose. Then all that remains is to open the panel and check each LED separately. Usually, Chinese multimeters with 9V power supply lightly light up one 3-volt LED, if you connect the probes to it in the forward direction, the red probe to the anode, and the black one to the cathode. For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of the LED health. In the event of a malfunction of the LED, its zener diode will either be cut off or pierced in the K / Z.
- The TV does not turn on, the indicator signals the standby or operating mode, or blinks.
Repair or diagnostics of the TNP4G548 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 MB board, it is necessary to check its components MT29F1G08ABAEAH, K4B1G1646G-BCK0. 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.
In cases where there is no tuning for terrestrial or cable TV channels, you should make sure that the software is correct, as well as that the supply voltages on the terminals of the TDSA-G220D tuner match. It is also necessary to check with an oscilloscope the presence of pulses of data exchange between the tuner and the processor via the I2C bus.
If the PANASONIC TX-LR50B6 has no picture, but there is sound, the backlight of the LC500DUE (SF) (R1) display 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.
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.Replacing the LEDs requires disassembling the LC500DUE 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
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 TNP4G548 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 TNP4G548 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.
Once again, we remind TV users: do not try to repair yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repairs to professionals with sufficient experience in the field of electronic repair.
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> PANASONIC TX-LR50B6 Chassis KM21E
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> TNPA5807 Power supply
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> TNP4G549 LED Driver
The MainBoard TNP4G548 is shown in the figure below:TNP4G548
External view of the power supply
The main features of the PANASONIC TX-LR50B6 device:
The matrix (LED panel) LC500DUE-SFR1 is installed.
Matrix control uses the Timing Controller (T-CON) 6870C-0452A.
To power the backlight LEDs, the TNP4G549 LED driver is used, controlled by the BL0200C PWM controller (C1ZBZ0004953). The keys of the B1CFRM000028, B1CFML000007 types are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the PANASONIC TX-LR50B6 TV is carried out by the TNPA5807 power module, or its analogs using the FA5696N, FA5760N, LV5980MC microcircuits and power switches of the STD7NM60N, STD7NM60N type.
MainBoard - the main board (motherboard) is a TNP4G548 module, using Peaks-sLD8, MT29F1G08ABAEAH, K4B1G1646G-BCK0 and others.
Tuner TDSA-G220D (J3ACAAC00008) provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LC500DUE-SFR1
Type: a-Si TFT-LCD, Panel
Diagonal size: 50 inch
Resolution: 1920x1080, FHD
Display Mode: IPS, Normally Black, Transmissive
Active Area: 1095.84x616.41 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Brightness: 300 cd / m²
Contrast Ratio: 1200: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 6 (G to G)
Frequency: 60Hz
Lamp Type: WLED Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V
TV PANASONIC TX-LR50B6 with LCD LC500DUE, diagonal size 50 "(127 cm) 16: 9 format. The technology of manufacturing the screen of this TV model is realized with LED backlighting.
The LC500DUE panel and the TNP4G548 motherboard firmware provide HD and Full HD viewing at 1920x1080 pixels in 1080p (Full HD) graphics. 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 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, RGB, HDMI x2, USB. 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.
The power consumed by the TV in operating mode from the mains is 136 W.
Dimensions: with stand 1139x739x275 mm, without stand 1139x674x89 mm.
TV weight: with stand: 18 kg, without stand: 15 kg.
Attention! The LC500DUE (SF) (R1) panel of the PANASONIC TX-LR50B6 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.
