Monday 6 April 2020

REPAIR / SERVICING TV AKAI LTA-2073

Technical description and composition of the AKAI LTA-2073 TV, panel type and applicable modules. The composition of the modules.
AKAI
Model: LTA-2073
Chassis / Version: CV075GT_V3
Panel: M201EW02
Lamp backlight: 4 Lamp CCFL
Inverter (backlight): for 4 Lamp 12V
Power Supply (PSU): Adapter 12V
MainBoard: CV075GT_V3
IC MainBoard: CPU: MST718BE-LF SPI FLASH: EN25D20 (D20-100GCP), EEPROM: MIC24LC16BI, SWITCH: HCF4052, AUDIO: TDA1517P + MSP3415G B8 V3
Tuner: TSN3311-Q
Control: Remote: GCOVA1028SJ
Technical specifications LTA-2073
AKAI LTA-2073
General recommendations for repairing TV LCD
Possible malfunctions
- The AKAI LTA-2073 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.
In such cases, the adapter power supply is usually faulty.
The external adapter 12V power supply is not always subject to repair, especially since the owner can purchase it independently. But, in some cases, it makes sense to open it and eliminate the simple typical defects inherent in converters in pulsed sources. It is necessary to measure its output voltages and, if they are absent, to check for short-circuit probabilities in the converters, power switches and rectifier diodes.
In the event of a breakdown in the secondary circuits of the converter, it can usually fail in short circuit mode, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse or current sensor at the source of the key most 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 microcircuits are usually checked by replacement with new ones, or obviously working.
- There is no image, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn on and immediately disappears.
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 the inverter.After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, you must ring in its converter power keys for breakdown and secondary windings of transformers for an open.
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 TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the CV075GT_V3 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). When repairing an MB board, you need to check its CPU components: MST718BE-LF SPI FLASH: EN25D20 (D20-100GCP), EEPROM: MIC24LC16BI, SWITCH: HCF4052, AUDIO: TDA1517P + MSP3415G B8 V3. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
If there is no reception of television channels, but the TV is working properly from external devices, first of all you need to check the voltage of the tuner TSN3311-Q and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Once again, remind users! Attempts to self-repair a TV AKAI LTA-2073 without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!


FIRMWARE FOR SPI FLASH  ----------->   AKAI LTA-2073, Main: CV075GT_V3, Panel: M201EW02

 The appearance of MainBoard CV075GT_V3 is shown in the figure below:
CV075GT_V3
Key features of the AKAI LTA-2073 device:
Installed matrix (LCD-panel) M201EW02.
The inverter is used to power the backlight.
To power all internal components of the AKAI LTA-2073 TV, an external adapter 12V type is used.
MainBoard - the main board (motherboard) is a CV075GT_V3 module, using CPU chips: MST718BE-LF SPI FLASH: EN25D20 (D20-100GCP), EEPROM: MIC24LC16BI, SWITCH: HCF4052, AUDIO: TDA1517P + MSP3415G B8 V3 and.
The TSN3311-Q tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: M201EW02 VG
Type: a-Si TFT-LCD, Panel
Diagonal size: 20.1 inch
Resolution: 1680x1050, WSXGA +
Display Mode: TN, Normally White, Transmissive
Active Area: 433.44x270.9 mm
Contrast Ratio: 1000: 1
Display Colors: 16.7M (6-bit + Hi-FRC)
Frequency: 60Hz
Signal Interface: LVDS (2 ch, 8-bit)
 Brand: AKAI, Model: LTA-2073.
Briefly from the TV: LCD, 20 ", 1680x1050, sound: 6 watts.
The composition uses MainBoard CV075GT_V3 and LCD-panel M201EW02.
Power supply unit external Adapter 12V.
AKAI LTA-2073 TV with an M201EW02 LCD display, a diagonal of 20 "in 16:10 format. Screen brightness of 300 cd / m² is ensured by backlighting with CCFL (EEFL) fluorescent lamps. The ratio of maximum brightness to minimum (contrast) is 1000: 1. The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation takes place in the standards 480i, 480p, 576i, 576p.
The power of the sound system 6 W (2x3 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 x2, S-Video, SCART, RGB, VGA. 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, 1280x1024.
The power consumed by the TV working in the network mode is 30 watts.
Overall dimensions: With stand 639x508x250 mm, Without stand 525x430x80 mm.
Attention! The M201EW02 panel of the AKAI LTA-2073 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!