Monday 6 April 2020

REPAIR / SERVICING TV AKAI LTA-2676P

Technical description and composition of the AKAI LTA-2676P TV, type of panel and applicable modules. The composition of the modules.
AKAI
Model: LTA-2676P
Panel: V260B1-L01 rev C2
Power Supply (PSU): WPL32H-6 rev 5.0
MainBoard: CV068M1
IC MainBoard: MST9E19A-LF, TPA3008D4052, Pi5V330SQT, Spi Flash: EN25F40, Eeprom: 24C32
Tuner: JS-6H2 / 121
Appearance
AKAI LTA-2676P
General recommendations for repairing TV LCD
Possible malfunctions
- The AKAI LTA-2676P TV does not turn on, does not respond to the remote control and the control panel buttons, the indicators do not light or flash.
With such manifestations, a malfunction is most likely detected in the WPL32H-6 power supply module. It is necessary to measure the secondary output voltage, and in case of their absence, check the serviceability of the power switches of the converters and rectifier diodes for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during a short circuit in the elements of the primary circuit, the mains fuse usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power supply, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. The PWM chip can also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and 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.
Sometimes, for diagnostic purposes, it is necessary to disable the inverter protection. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the CV068M1 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). If it is not possible to replace the MB (SSB) board, you need to check the health of its elements - MST9E19A-LF, TPA3008D4052, Pi5V330SQT, Spi Flash: EN25F40, Eeprom: 24C32. 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
Attention! Users and owners of LTA-2676P TVs who do not have the appropriate qualifications, knowledge and experience are strongly advised against self-repair attempts in order to avoid negative consequences that could lead to complete non-serviceability of the device.


Repair MainBoard
The appearance of the MainBoard CV068M1 is shown in the figure below:
CV068M1
CV068M1 can be used in TVs:
AKAI LTA-2676P (Panel V260B1-L01 rev C2), AKAI LTA-32N576HCP (Panel V315B3-L04).
Key Features of the AKAI LTA-2676P:
Installed matrix (LCD panel) V260B1-L01 rev C2.
The formation of the necessary supply voltages for all nodes of the AKAI LTA-2676P TV is carried out by the WPL32H-6 power module, or its analogues.
MainBoard - the main board (motherboard) is a CV068M1 module, using microcircuits MST9E19A-LF, TPA3008D4052, Pi5V330SQT, Spi Flash: EN25F40, Eeprom: 24C32 and others.
The JS-6H2 / 121 tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: CMO
Model: V260B1-L01
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
Surface: Antiglare (Haze 25%), Hard coating (3H)
Brightness: 500 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: 12 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V