Friday 10 April 2020

REPAIR / SERVICING TV AKIRA LCT-26MT02ST

Technical description and composition of the TV AKIRA LCT-26MT02ST, type of panel and applicable modules. The composition of the modules.
AKIRA
Model: LCT-26MT02ST
Chassis / Version: MSDV2601-ZC01-01
Panel: V260B1-L02 Rev. C1
Lamp backlight: 4 Lamp CCFL
T-CON: MSDV2601-ZC09-01-B 303C2601053
Inverter (backlight): integrated into PSU
PWM Inverter: SG3525AN
Power Supply (PSU): MIP260B-1
PWM Power: L656JD, F9222
MOSFET Power: 13N50C, 5N50CR
MainBoard: MSDV2601-ZC01-01 C 303C2601073
IC MainBoard: CPU: MST9E19A, Spi flash: W25X40, AT89C2051, CPU: MST9E19A, SOUND: STA540SA
Tuner: JS-6H2 / 121
Control: IR: TV1902-ZC25-01 (C)
Technical Specifications LCT-26MT02ST
AKIRA LCT-26MT02ST
General recommendations for repairing TV LCD
Possible manifestations of defects
- The AKIRA LCT-26MT02ST TV does not turn on and does not show any signs of operability at all. There is no reaction to the remote control and control buttons from the front panel.
Usually with such manifestations, the defect is caused by faulty elements in the MIP260B main power module. It is necessary to measure its output voltages, and in case of their absence, check the serviceability of power switches (13N50C, 5N50CR) of converters and rectifier diodes for a short circuit probability.
In case of breakdowns of semiconductors in the secondary circuits, the converter can usually work abnormally in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse often breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM circuits L656JD, F9222 are usually checked by replacing with new ones, or obviously working.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
These manifestations can be triggered by a power module, or by defects in the inverter, as well as a distortion of the currents in the lamps due to their uneven wear. After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, it is necessary to ring in its converter power keys for breakdown and secondary windings of transformers for an open.
Sometimes, for diagnostic purposes, inverter protection must be disabled. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- 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 motherboard MSDV2601-ZC01-01 should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). If it is not possible to replace the MB board (SSB), you need to check the health of its elements - CPU: MST9E19A, Spi flash: W25X40, AT89C2051, CPU: MST9E19A, SOUND: STA540SA. Defective components should be replaced.
Before changing the JS-6H2 / 121 tuner, if it is not possible to tune to television channels, make sure that there are supply voltages that must be measured at the corresponding tuner pins and checked for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Entrust repair to professionals with sufficient experience in the field of repair of electronic equipment.


SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    AKIRA Main MSDV2601-ZC01-01


 The appearance of the MainBoard MSDV2601-ZC01-01 is shown in the figure below:
MSDV2601-ZC01-01
MSDV2601-ZC01-01 can be used in TVs:
AKIRA LCT-D26MT05ST (Panel V260B1-L02 Rev.C1), AKIRA LCT-32MT04ST (Panel V315B1-L01 Rev.C3), AKIRA LCT-32MT05ST (Panel V315B1-L01 Rev.C2), MYSTERY MTV-2602W (Panel V260B1-L01 Rev.C2 ).
The appearance of the power supply
Key Features of the AKIRA LCT-26MT02ST:
Installed matrix (LCD panel) V260B1-L02 Rev. C1.
The matrix control uses the Timing Controller (T-CON) MSDV2601-ZC09-01-B.
To power the backlight, a converter is used, combined with a power supply, controlled by the SG3525AN PWM controller.
The necessary supply voltages for all nodes of the TV AKIRA LCT-26MT02ST are generated by the MIP260B-1 power module or its analogs using L656JD, F9222 microcircuits and 13N50C, 5N50CR type power switches.
MainBoard - the main board (motherboard) is an MSDV2601-ZC01-01 module, using CPU chips: MST9E19A, Spi flash: W25X40, AT89C2051, CPU: MST9E19A, SOUND: STA540SA and others.
The JS-6H2 / 121 tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: CMO
Model: V260B1-L02
Type: a-Si TFT-LCD, Panel
Diagonal size: 26.0 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 575.769x323.712 mm
Brightness: 450 cd / m²
Contrast Ratio: 800: 1
Display Colors: 16.2M (6-bit + FRC), CIE1931 72%
Response Time: 3/5 (Tr / Td)
Frequency: 60Hz
Lamp Type: 4 pcs CCFL Without Driver
Signal Interface: RSDS (1 Channel), 45 pins
Voltage: 5.3.3 / 5.0V (VDD / VIN5)

 Brand: AKIRA, Model: LCT-26MT02ST.
Short from TV: LCD, 26 ", 1366x768, 720p HD, sound: 16 watts.
The composition uses MainBoard MSDV2601-ZC01-01 C 303C2601073 and LCD-panel V260B1-L02 Rev. C1.
Power Supply Unit (PSU) MIP260B Power Supply.
AKIRA LCT-26MT02ST TV with V260B1-L02 LCD display, 26 "(66 cm) diagonal size in 16: 9 format. 500 cd / m² screen brightness is provided by CCFL (EEFL) lamps. Contrast - the ratio of maximum brightness to minimum is not less than 800: 1. It is possible to view in high quality HD at a resolution of 1366x768 pixels in 720p standard (HD Ready). The input high-frequency or video signal is decoded in PAL, SECAM, NTSC analog systems. Digital signal generation (graphic format) is performed in 480i, 480p standards , 576i, 576p, 720p, 1080i.
The power of the sound system 16 W (2x8 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, RGB, VGA, HDMI. A headphone jack is provided. A standard VGA (D-Sub 15) connector is used to connect a laptop or computer. This interface supports resolutions: 640x480, 800x600, 1024x768, 1360x768.
Overall dimensions: With stand 731x468x166 mm, Without stand 731x437x87 mm.
Attention! The AKIRA LCT-26MT02ST LCD TV panel V260B1-L02 Rev. C1 is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!