Monday 6 April 2020

REPAIR / SERVICING TV AKAI LTA-32R5W4HCM

Technical description and composition of the AKAI LTA-32R5W4HCM TV, panel type and applicable modules. The composition of the modules.
AKAI
Model: LTA-32R5W4HCM LTA-32R5W4HCP
Chassis / Version: 9E19V6.1-C
Panel: LTA320AP02
Inverter (backlight): integrated into PSU
PWM Inverter: OB6563CP
MOSFET Inverter: K3683
Power Supply (PSU): VP228UG01 VER1.0
PWM Power: DM0365R, L6599D
MOSFET Power: 08N60GX
MainBoard: 9E19V6.1-C
IC MainBoard: F40-100GCP, 24LC32AJ, CAT6353CQ, TDA7266SA, MT1389DE
Tuner: CDT-6GPL28-00
Technical Specifications LTA-32R5W4HCM
AKAI LTA-32R5W4HCM
General recommendations for repairing TV LCD
Possible manifestations of defects
- The AKAI LTA-32R5W4HCM TV does not turn on and does not show any signs of turning on, does not respond to the control buttons or to the remote control.
Most likely in this case, the main switching power supply (IIP) VP228UG01 is faulty. It is necessary to verify the presence of its output voltages and, if they are completely absent, check the power switches (08N60GX) and rectifier diodes for a probable short circuit.
In case of breakdowns of semiconductors in 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 microcircuits (PWM) DM0365R, L6599D are usually checked by replacing with new ones, or obviously working.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned 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 9E19V6.1-C 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). In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its chips F40-100GCP, 24LC32AJ, CAT6353CQ, TDA7266SA, MT1389DE and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
If the TV works normally from external devices, but does not tune to television channels, the tuner CDT-6GPL28-00 may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Owners and users of the AKAI LTA-32R5W4HCM TV should remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!



Repair MainBoard
The appearance of MainBoard 9E19V6.1-C is shown in the figure below:
9E19V6.1-C
The appearance of the power supply
Key Features of the AKAI LTA-32R5W4HCM:
Installed matrix (LCD-panel) LTA320AP02.
To power the backlight, a converter is used, combined with the power supply, controlled by the OB6563CP PWM controller. As power elements of the inverter, keys of the K3683 type are used.
The necessary supply voltages for all nodes of the TV AKAI LTA-32R5W4HCM are generated by the VP228UG01 power module or its analogs using DM0365R, L6599D microcircuits and 08N60GX type power switches.
MainBoard - the main board (motherboard) is a module 9E19V6.1-C, using chips F40-100GCP, 24LC32AJ, CAT6353CQ, TDA7266SA, MT1389DE and others.
The tuner CDT-6GPL28-00 provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTA320AP02
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: PVA, Normally Black, Transmissive
Active Area: 697.68x392.26 mm
Surface: Antiglare (Haze 7%), Hard coating (3H)
Brightness: 450 cd / m²
Contrast Ratio: 5000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 8 (G to G)
Frequency: 60Hz
Lamp Type: 4 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins

Voltage: 12.0V

Brand: AKAI, Model: LTA-32R5W4HCM.
Briefly from the TV: LCD, 32 ", 1366x768, 720p HD, sound: 16W, HDMI: 2.
The composition uses MainBoard 9E19V6.1-C and an LCD panel (matrix) LTA320AP02.
Power Supply Unit (PSU) VP228UG01 VER1.0 Power Supply.
AKAI LTA-32R5W4HCM TV with a 32 "(81 cm) diagonal LCD display, 32: 9 format. LCD screen brightness of 450 cd / m² is provided by CCFL (EEFL) fluorescent lamps. Dynamic contrast ratio of 5000: 1 is achieved by special control of operation 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 standards 480i, 480p, 576i, 576p, 720p, 1080i Supported media file formats: MP3, WMA.
The power of the sound speaker system 16 W (2x8 W) is provided by 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 x2, RGB, VGA, HDMI x2, USB. 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, 1360x768.
The power consumed by the TV working in the network mode is 160 watts.
Overall dimensions: With stand 810x616x252 mm, Without stand 810x560x112 mm.
Attention! The LTA320AP02 panel of the AKAI LTA-32R5W4HCM 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!