Thursday 9 April 2020

REPAIR / SERVICING TV AIWA 32LE7020S

Technical description and composition of the TV AIWA 32LE7020S, type of panel and applicable modules. The composition of the modules.
AIWA LED
Model: 32LE7020S
Chassis / Version: 5800-A7N01G-0P10
Panel: LC320DXJ (SH) (A2) // ST3151A05-8 VER2.4
LED backlight: JL.D32061330-001QS-M YAL13-00630300-24 (ST3151)
T-CON: MT3151A05-5-XC-9
LED driver (backlight): integrated into MainBoard
Power Supply (PSU): integrated into MainBoard
PWM Power: SOIC8
MOSFET Power: TO-252
MainBoard: 5800-A7N01G-0P10 VER00.05
IC MainBoard: SPI Flash: 25L1606E. AUDIO: TAS5707
Tuner: 5800-J7N01G-0P00 + SAT
Specifications 32LE7020
AIWA 32LE7020S
General repair guidelines for TV LCD LED
Possible manifestations of defects
- TV AIWA 32LE7020S does not turn on at all. The control lights do not light or flash. The TV on the remote control and the control panel buttons do not respond.
The malfunction in such cases should be sought in the elements of the power source - the network voltage converter (AC / DC), which is located on the MainBoard 5800-A7N01G-0P10 main board. It is necessary to measure its output voltages and, if they are absent, to check for short circuit probability in the converters power switches (TO-252) and rectifier diodes.
In case of breakdowns in the secondary circuits, the converter, as a rule, can emergency work in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse usually breaks.
Breakdown of power switches (MosFet) in pulsed sources is sometimes caused by malfunctions of other circuit elements, for example, in circuits supplying a PWM controller, frequency-setting or damper ones, as well as in negative feedback (OOS) stabilization circuits. PWM controllers (PWM) SOIC8, if they do not have visible damage to the case and open fault between the terminals, are usually checked by replacement.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
Usually in such cases there is no backlight LED-panel (matrix). The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
To check the LED lines for breaks without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter, a voltage of the order of several tens of volts is required.
- 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 5800-A7N01G-0P10 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). Often, the MB (SSB) card must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - SPI Flash: 25L1606E. AUDIO: TAS5707 and replace failed chips with new ones. Some malfunctions may be due to the use of BGA soldering technologies in modern Main Board technologies. Typically, such defects are detected by local heating of the chip.
In the absence of tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltage at the terminals of the tuner 5800-J7N01G-0P00 + SAT. It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
Attention to users! Self-repair of the TV AIWA 32LE7020S without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!


FIRMWARE FOR SPI FLASH  ----------->   AIWA 32LE7020S V1S11, Main: 5800-A7N01G-0P10, Panel: LC320DXJ (SH)(A2)
 The appearance of the MainBoard 5800-A7N01G-0P10 is shown in the figure below:
5800-A7N01G-0P10
Key Features of AIWA 32LE7020S:
Installed matrix (LED-panel) LC320DXJ (SH) (A2) or ST3151A05-8 VER2.4.
The matrix control uses the Timing Controller (T-CON) MT3151A05-5-XC-9.
To power the backlight LEDs, a converter is used, combined with the main board 5800-A7N01G-0P10.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter using SOIC8 microcircuits and TO-252 type power switches.
MainBoard - the main board (motherboard) is a 5800-A7N01G-0P10 module, using SPI Flash chips: 25L1606E. AUDIO: TAS5707 and others.
The tuner 5800-J7N01G-0P00 + SAT provides TV reception and channel tuning.