Wednesday, 2 September 2020

REPAIRING / SERVICING TV PANASONIC TX-26LX60P

Technical description and composition of the PANASONIC TX-26LX60P TV, panel type and modules used. The composition of the modules.
PANASONIC
Model: TX-26LX60P
Chassis / Version: GLP21
Panel: LTA260W2-L09
Lamp backlight: 6 Lamp CCFL
Inverter (backlight): INVUT260A rev.09
PWM Inverter: BD9883AF
Power Supply (PSU): TNP8EPL50 PL50AFNS AD-TP3
PWM Power: F9222
MOSFET Power: 2SK3767
MainBoard: TNP8EAL40
IC MainBoard: VCT 6973G B2 000, 24C32AN, TDA8931T
Tuner: TXN / BL50AERS
TX-26LX60P Specifications
PANASONIC TX-26LX60P
General recommendations for TV LCD repair
Possible manifestations of malfunctions
- PANASONIC TX-26LX60P TV does not turn on at all. Control lamps do not light up or blink. The TV on the remote control and control panel buttons does not respond.
In some of these cases, the fault is detected in the TNP8EPL50 power supply module. It is necessary to measure its output supply voltages, and in their absence, check the serviceability of the power switches (2SK3767) of the converters and rectifier diodes for the probability of breakdown in semiconductor PN junctions.
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually operate normally in an emergency short-circuit mode. There are no output voltages. And with a short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and, less often, the current sensor in the source of the key.
Mos-Fet power switches used in switching power supplies sometimes fail due to a malfunction of any other elements that can disable it in the key mode, or create an excess of the maximum permissible key parameters. These can be elements supplying a PWM regulator, frequency setting or damper circuits, or elements of negative feedback in the stabilization circuit. PWM controllers F9222, in the absence of visible damage or outright short circuits between the terminals, are checked by replacing them with new ones, or knowingly working properly.
- 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.
A defect can be caused by problems in the nodes or elements of the display backlight, or in the power supply of lamps or the inverter.After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, ring the power switches in its converter for breakdown and the secondary windings of the transformers for an open circuit.
If, when diagnosing a malfunction, it is required to turn off the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during work, and after they are completed, it is imperative to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- 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 TNP8EAL40 motherboard should begin with checking the stabilizers and power converters required to power the microcircuits and the matrix. If necessary, you should update or replace the software (software). Repair of the board and replacement of the VCT 6973G B2 000, 24C32AN, TDA8931T microcircuits are carried out if the necessary equipment and the corresponding element base are available. Malfunctions associated with the use of BGA soldering technologies can be localized by the warm-up method.
If 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 TXN / BL50AERS tuner outputs 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.
Owners and users of the PANASONIC TX-26LX60P TV should remember that self-repair without special knowledge, skills and qualifications may be fraught with negative consequences that can lead to complete non-repairability of the device!


DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    PANASONIC TX-26LX60P Chassis GLP21. for models  TX-32LX60F, TX-32LX60P, TX-26LX60F, TX-26LX60P


 MainBoard TNP8EAL40 is shown in the figure below:
TNP8EAL40
External view of the power supply
Main features of the PANASONIC TX-26LX60P device:
Installed matrix (LCD-panel) LTA260W2-L09.
The inverter INVUT260A is used to power the backlight lamps, it is controlled by the PWM controller BD9883AF.
The formation of the necessary supply voltages for all nodes of the PANASONIC TX-26LX60P TV is carried out by the TNP8EPL50 power module, or its analogs using F9222 microcircuits and 2SK3767 power switches.
MainBoard - the main board (motherboard) is a TNP8EAL40 module, using the VCT 6973G B2 000, 24C32AN, TDA8931T and others.
The TXN / BL50AERS tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTA260W2-L09
Type: a-Si TFT-LCD, Panel
Diagonal size: 26.0 inch
Resolution: 1366x768, WXGA
Display Mode: PVA, Normally Black, Transmissive
Active Area: 575.769x323.712 mm
Surface: Antiglare (Haze 44%), Hard coating (3H)
Brightness: 450 cd / m²
Contrast Ratio: 1200: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 16/6 (Tr / Td); 8 (G to G)
Frequency: 60Hz
Lamp Type: 6 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V
PANASONIC TX-26LX60P TV with LCD LTA260W2, 26 "(66 cm) 16: 9. Brightness of the screen 550 cd / m² provided by CCFL (EEFL) fluorescent lamps. Contrast, as the ratio of maximum brightness to minimum, is 1200: 1.
The LTA260W2 panel and TNP8EAL40 firmware can display HD images at 1366x768 pixels for 720p graphics resolution (HD Ready). 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.
The power of the acoustic audio system 20 W (2x10 W) is provided by two 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, audio x2, S-Video, component, SCART x2, RGB, HDMI x2. A headphone output is provided for individual listening. To connect a computer or laptop, a VGA (D-Sub 15) connector is used that supports resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768.
Dimensions: with stand 657x525x301 mm, without stand 657x473x107 mm.
TV weight: without stand: 14.5 kg.
Attention! Panel LTA260W2 6LP L5EDD6Q00013 LCD TV PANASONIC TX-26LX60P is a rather expensive component.
Avoid impacts on glass and pressure on the surface of the screen to avoid irreversible damage to the LCD panel!