Technical description and composition of the TV AKAI LEA-50V28P, type of panel and modules used. Module composition.
AKAI LED
Model: LEA-50V28P
Chassis/Version: TP.VST59S.PC815
Panel: T500HVN01.1 // A500AD1D01-1
LED driver (backlight): integrated into MainBoard
PWM LED driver: PWM SOT23-6
Power Supply (PSU): integrated into MainBoard
PWM Power: NCP1607 (PFC), PWM SOT23-6
MOSFET Power: 60R580P, TF8N80
MainBoard: TP.VST59S.PC815
MainBoard IC: CPU: TSUMV59XUS, SPI FLASH: GD25Q32
Tuner: NoName
Specifications LEA-50V28P
AKAI LEA-50V28P
General advice about LCD LED TV repair
Possible defects
- AKAI LEA-50V28P does not turn on, the indicators on the front panel do not light up or blink. TV does not respond to the control buttons and remote control.
In these cases the problem must be sought in the elements of the power supply - AC/DC converter, which is located on the main board MainBoard TP.VST59S.PC815. It is necessary to measure its output voltages, and in case of their absence check the serviceability of the power keys (60R580P, TF8N80) converters and the rectifier diodes for the probability of short circuit.
With any breakdown of semiconductors in the secondary circuits, the inverter can usually operate normally in the emergency short-circuit mode. There are no output voltages in this case. And when a short circuit occurs in the power elements of the primary circuit, as a rule, the mains fuse and rarely the current sensor at the source of the switch break down.
Mos-Fet power switches, used in switching power supplies, sometimes fail because of failure of any other elements, which can take it out of the key mode, or create exceeding the maximum allowable parameters of the switch. These can be elements that feed the PWM controller, the frequency-retaining or damping circuits, or negative feedback elements in the stabilization circuit. PWM controllers NCP1607 (PFC), PWM SOT23-6, if there is no visible damage or outright short circuit between the pins are checked by replacing with new or known good ones.
- No picture, but there is sound and all other TV functions work. The picture sometimes appears for a second immediately after switching on and then disappears.
Faulty in these cases is usually the backlight of the matrix (LED panel). The reason for this may be a breakage in the circuit of the LEDs, or a problem with their power supply stabilization.
When trying to identify a breakage in the lines of LEDs, you should keep in mind that it is difficult to do without disassembling the panel. For example a current source is needed to open the PN-junctions connected in series.
- The TV doesn't turn on, the remote control doesn't respond. Indicator blinks or signals standby mode.
Repair or diagnostic of the TP.VST59S.PC815 motherboard should begin with checking the stabilizers and power converters necessary to power the chips and matrix. If necessary, update or replace the software (firmware). If you tried to repair MB board (SSB), you must check the functionality of its elements: CPU: TSUMV59XUS, SPI FLASH: GD25Q32 that may need replacement for new ones. If you have a BGA processor, there is a possibility of breaking the solder connection between its pins and the board (can be diagnosed by heating).
Before changing the NoName tuner, if you cannot tune to the TV channels, make sure the supply voltages are present and measure them on the corresponding pins of the tuner and check the software for correctness. The tuner to processor communication pulses can be checked with an oscilloscope
For masters :
If AKAI LEA-50V28P has no picture, but there is sound, often the display backlight T500HVN01.1 simply does not work. Moreover, in LED-TVs usually fail LEDs inside the panel, less often the LED-driver.
In such cases, you can see a faintly visible image when external light hits the screen.
To replace the LEDs requires disassembly of the LCD-panel T500HVN01.1 - the process requiring the master of experience and skill. We do not recommend to perform such works by yourself to owners of TV sets and craftsmen who have no experience in LCD panel repair
If there is no image, but backlighting works - the screen becomes slightly lighter when the TV is switched on, and in the open TV you can see the light through the holes in the body of the panel.
In this case the panel may be defective - damage to the strips, cables, for example, as a consequence of moisture after an unsuccessful washing of the screen, the T-CON board (Timing Controller) may be defective. But quite often the MainBoard TP.VST59S.PC815 is faulty as well, so software defects are also possible.
Then first it is necessary to check the panel power supply voltage, the fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within normal limits, you need to trace by oscilloscope the LVDS signals from MainBoard TP.VST59S.PC815, as well as synchronizing signals to driver stubs.
Flooded or badly washed LED TV screens can be repaired in about half of the cases, usually if there is no significant damage to the panel stubs and slats.
Please remember! Attempts to repair TV AKAI LEA-50V28P by yourself, if you do not have the necessary skills and experience, is strongly not recommended and is fraught with negative consequences, up to the complete unrepairable device!
DOWNLOAD FIRMWARE FOR SPI FLASH -----------> AKAI LEA-50V28P, Main: TP.VST59S.PC815, Panel: T500HVN01.1 108W4
After repair of the backlight. TP.VST59S.PC815. Information from the REPAIR master.
Reduced backlight current from 600 mA to 400 mA - Increased the rating of the measuring resistor (current sensor) RB337 from 0.68 Ohm to 1 Ohm.
More on MainBoard repairs
The MainBoard TP.VST59S.PC815 is shown in the figure below:
TP.VST59S.PC815
The main features of the device AKAI LEA-50V28P:
A matrix (LED panel) T500HVN01.1 or A500AD1D01-1 is installed.
To power the backlight LEDs is used converter, combined with the main board TP.VST59S.PC815, controlled by PWM controller PWM SOT23-6.
The power module is integrated into the MainBoard and is designed as a reverse-going AC/DC converter with NCP1607 (PFC), PWM SOT23-6 chips and 60R580P, TF8N80 power switches.
MainBoard - the main board (motherboard) is a module TP.VST59S.PC815, with the use of chip CPU: TSUMV59XUS, SPI FLASH: GD25Q32 and others.
The NoName tuner provides reception of TV programs and tuning to channels.
More technical information about the panel:
Brand : AUO
Model : T500HVN01.1 CELL
Type : A-Si TFT-LCD, CELL
Diagonal size : 50 inch
Resolution : 1920x1080, FHD
Display Mode : AMVA3, Normally Black, Transmissive
Active Area : 1095.84x616.41 mm
Surface : Antiglare (Haze 2%), Hard coating (3H)
Glass Depth : 0.50+0.50 mm
Transmissivity : 6.5% (with Polarizer)
Contrast Ratio : 3000:1
Display Colors : 16.7M (8-bit), CIE1931 72%
Response Time : 6.5 (G to G)
Frequency : 60Hz
Signal Interface : LVDS (2 ch, 8/10-bit), 51 pins
Voltage : 12.0V
AKAI LEA-50V28P TV with LCD display A500AD1D02-1, measuring 50" (127 cm) diagonally in 16:9 aspect ratio. 250 cd/m² brightness is provided by an LED backlight with a maximum to minimum brightness ratio (contrast ratio) of 5000:1. This model has Edge LED side illumination.
LCD panel A500AD1D02-1 and MainBoard software TP.VST59S.PC815 provide for high quality HD image realization with 1920x1080 pixels resolution in 1080p (Full HD) graphic decomposition. The input antenna or video signal can be processed in PAL, SECAM, NTSC analog systems. Graphical processing and formation of a digital signal is carried out in standards 480i, 480p, 576p, 576p, 720p, 1080i. Supported media file formats: MP3, WMA, MPEG4, Xvid, DivX, MKV, JPEG.
The sound system has a capacity of 16 W (2x8 W), provided by two speakers. NICAM STEREO audio processing system is used.
External interface (connection with other devices) is supported by standard inputs and outputs: antenna input (RF), AV x2, audio x3, component, VGA, HDMI x2, USB x2. There is a headphone output. To connect a computer or laptop to this TV model uses a VGA (D-Sub 15) connector on the TV body, this interface supports resolutions: 640x480, 800x600, 1024x768, 1920x1080.
The TV uses a power supply as part of the MainBoard.
Overall dimensions: With stand 1132x703x210 mm, without stand 1132x665x74 mm.
Weight of the TV: 10 kg.
Warning. The panel A500AD1D02-1 LED-TV AKAI LEA-50V28P is an expensive and unreliable element of the TV.
Do not allow any impact on the glass and pressure on the screen surface to avoid damaging the LED panel!
Also it is not safe to get liquid on the screen. Sometimes one drop is enough if it drips down the glass onto the cables and the TV becomes unrepairable.