Monday 6 April 2020

REPAIR / SERVICING TV AKAI LTA-26N573HCA

Technical description and composition of the AKAI LTA-26N573HCA TV, panel type and applicable modules. The composition of the modules.
AKAI
Model: LTA-26N573HCA
Chassis / Version: B.TR901E
Panel: T260XW02 V.6
Inverter (backlight): 4H.V0708.361 / F
PWM Inverter: 0Z964SN
MOSFET Inverter: P2804BDG, P5506EOG
Power Supply (PSU): MLT668TL REV 1.5
PWM Power: L6562D, LD7535, SG3525
MOSFET Power: 13N50C, 5N50CF
MainBoard: B.TR901E 7432
IC MainBoard: SVP-AX68, EM6A9160TC-4G, TDA9886TS, W25X80A, 24C64
Tuner: TDQ-6F6 / T1260W
Technical Specifications LTA-26N573HCA
AKAI LTA-26N573HCA
General recommendations for repairing TV LCD
Possible manifestations of defects
- AKAI LTA-26N573HCA does not turn on, the indicators on the front panel do not light or flash. The TV does not respond to the control buttons and the remote control.
With such manifestations, the MLT668TL power supply module usually fails. It is necessary to measure its output voltages, and in case of their absence, check the serviceability of power switches (13N50C, 5N50CF) of converters and rectifier diodes for a short circuit probability.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in emergency short-circuit mode without output voltages, and during short circuit in the elements of the primary circuit, the main fuse and, less often, the current sensor at the source of the key are most often cut off.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damping circuits, or negative feedback elements in the stabilization circuit. PWM controllers L6562D, LD7535, SG3525, in the absence of visible damage or obvious short-circuit between the terminals, are checked by replacing with new ones, or obviously working.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or inverter. If all the electrolytic capacitors of the filter according to the power supply of the inverter are working, make sure that the lamps are working, then you need to check the converter keys and the secondary windings of the transformers.
If in diagnosing a malfunction, it is necessary to disable 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 their completion, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the B.TR901E motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Verification or replacement of elements SVP-AX68, EM6A9160TC-4G, TDA9886TS, W25X80A, 24C64 requires the necessary training and professional skills in repairing modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by warming up.
The malfunction of the TDQ-6F6 / T1260W tuner is established after checking the software and all the supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be controlled by an oscilloscope.
Attention! Users and owners of LTA-26N573HCA TVs who do not have the appropriate qualifications, knowledge and experience are strongly discouraged from attempting self-repair in order to avoid negative consequences that could lead to complete non-serviceability of the device.




The appearance of the MainBoard B.TR901E is shown in the figure below:
B.TR901E
B.TR901E can be used on TVs:
AKAI LTA-26N573HCA (Panel T260XW02 V.6), HYUNDAI H-LCD3202 (Panel LTA320AB02), IZUMI TL32H413B (Panel LTA320AB02).
The appearance of the power supply
Key Features of the AKAI LTA-26N573HCA:
Installed matrix (LCD panel) T260XW02 V.6.
To power the backlight, an inverter 4H.V0708.361 is used, it is controlled by a PWM controller 0Z964SN. As power elements of the inverter, keys of the type P2804BDG, P5506EOG are used.
The required supply voltages for all nodes of the TV AKAI LTA-26N573HCA are generated by the MLT668TL power supply module or its analogs using L6562D, LD7535, SG3525 microcircuits and 13N50C, 5N50CF type power switches.
MainBoard - the main board (motherboard) is a B.TR901E module, using chips SVP-AX68, EM6A9160TC-4G, TDA9886TS, W25X80A, 24C64 and others.
The TDQ-6F6 / T1260W tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: T260XW02 V6
Type: a-Si TFT-LCD, Panel
Diagonal size: 26.0 inch
Resolution: 1366x768, WXGA
Display Mode: AMVA, Normally Black, Transmissive
Active Area: 575.769x323.712 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 1200: 1
Display Colors: 16.7M (8-bit)
Response Time: 15/5 (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
Brand: AKAI, Model: LTA-26N573HCA.
Shortly from the TV: LCD, 26 ", 1366x768, 720p HD, sound: 12 W, HDMI connectors: 2.
The composition uses MainBoard B.TR901E 7432 and LCD-panel T260XW02 V.6.
Power Supply Unit (PSU) MLT668TL REV 1.5 power Supply.
AKAI LTA-26N573HCA TV with a 26 ”(66 cm) diagonal LCD display, 16: 9 format. Screen brightness of 500 cd / m² is provided by CCFL (EEFL) fluorescent lamps. The ratio of maximum brightness to minimum (contrast) is 800: 1. It is possible to view images in high quality HD at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in the standard max 480i, 480p, 576i, 576p, 720p, 1080i.
The power of the sound system 12 W (2x6 W) provide two speakers. The audio processing system NICAM STEREO is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x3, S-Video, component, SCART x2, RGB, VGA, HDMI x2. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector is used on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768.
The power consumed by the TV working in the network mode is 160 watts.
Overall dimensions: 660x510x240 mm.
The mass of the TV: 11 kg.
Attention! The T260XW02 V.6 panel of the AKAI LTA-26N573HCA LCD TV is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!