Monday 4 May 2020

REPAIR / SERVICING TV IZUMI TLE42F400B

Technical description and composition of the IZUMI TLE42F400B TV, type of panel and applicable modules. The composition of the modules.
IZUMI LED
Model: TLE42F400B
Chassis / Version: MST6M181VS-V3.0
Panel: V420H2-LE3 REVC3
LED backlight: MD30445DE-A
T-CON: V420H2-CS1
LED driver (backlight): T87D159.00
PWM LED driver: GB2500, BA2902F
Power Supply (PSU): AY130D-4SF01 AY1136A69297
MainBoard: MST6M181VS-V3.0
IC MainBoard: TAD7266, MSH9010-LF (24), M13S2561616A, PS331
Tuner: CDT-3BP5I2-36
Technical Specifications TLE42F400B
IZUMI TLE42F400B
General repair guidelines for TV LCD LED
Possible malfunctions
- IZUMI TLE42F400B does not turn on, the indicators on the front panel do not light or flash. The TV does not respond to the control buttons and the remote control.
In some of these cases, the main switching power supply, the AY130D-4SF01 module, turns out to be faulty. It is necessary to measure its output supply voltage, and in case of their absence, check the serviceability of the power switches of the converters and rectifier diodes for the probability of breakdown in semiconductor PN junctions.
In case of diode breakdowns in the secondary circuits, the converter can operate in emergency short-circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM), in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- 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.
In such cases, the most likely malfunction of the LED backlight elements. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
When trying to detect a break in the LED lines, it should be taken into account that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the MST6M181VS-V3.0 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) card, you need to check the health of its elements - TAD7266, MSH9010-LF (24), M13S2561616A, PS331. Defective components should be replaced.
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 CDT-3BP5I2-36. 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! Independent repair of the IZUMI TLE42F400B TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!

Repair MainBoard
The appearance of the MainBoard MST6M181VS-V3.0 is shown in the figure below:
MST6M181VS-V3.0
MST6M181VS-V3.0 can be used in TVs:
IZUMI TLE32H410M (Panel V315B5-LE3 REV.C2), IZUMI TLE26H400B (Panel T260XBNO V.0), IZUMI TLE42F400B (Panel V420H2-LE3 REVC3).
The appearance of the power supply
Main features of the IZUMI TLE42F400B device:
Installed matrix (LED-panel) V420H2-LE3 REVC3.
The matrix control uses the Timing Controller (T-CON) V420H2-CS1.
The LED driver T87D159.00 is used to power the backlight LEDs, it is controlled by the GB2500, BA2902F PWM controller.
The formation of the necessary supply voltages for all nodes of the IZUMI TLE42F400B TV is carried out by the power module AY130D-4SF01, or its analogues.
MainBoard - the main board (motherboard) is an MST6M181VS-V3.0 module, using TAD7266, MSH9010-LF (24), M13S2561616A, PS331 and others.
The tuner CDT-3BP5I2-36 provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: V420H2-LE3 Rev. C3
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 930.24x523.26 mm
Surface: Antiglare (Haze 11%), Hard coating (3H)
Brightness: 450 cd / m²
Contrast Ratio: 6000: 1
Display Colors: 1.07B (8-bit + Hi-FRC), CIE1931 72%
Response Time: 5.5 (G to G)
Frequency: 120Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (4 ch, 10-bit), 92 pins Voltage: 12.0V