Friday 3 April 2020

REPAIR / SERVICING TV TOSHIBA 40TL968

Technical description and composition of the TOSHIBA 40TL968 TV, panel type and applicable modules. The composition of the modules.
TOSHIBA LED
Model: 40TL968
Chassis / Version: PE1091
Panel: LTA400HV04
LED backlight: SLED 2012SGS40 7030L 56LED
T-CON: 12PSQBC4LV0.0
LED driver (backlight): integrated into PSU
PWM LED driver: SSL110SN
Power Supply (PSU): N150A002L N11-150P1A
PWM Power: A6069, FAN6961 (PFC), L6577B
MOSFET Power: K12A50D
MainBoard: PE1091 V28A001434C1
IC MainBoard: MSD8881, K4B2G1646E, K4B1G1446G, TAS5708
Tuner: TDSS-G224D & TSU25-E02
Specifications 40TL968
TOSHIBA 40TL968
General repair guidelines for TV LCD LED
Possible manifestations of defects
- TOSHIBA 40TL968 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 such cases, the fault should be sought first in the power module N150A002L. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches and rectifier diodes for a possible partial or complete breakdown.
In case of any breakdowns in the secondary circuits, the converter can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key more often breaks.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damping circuits, or negative feedback elements in the stabilization circuit. PWM controllers A6069, FAN6961 (PFC), L6577B, in the absence of visible damage or explicit short-circuit between the terminals, are 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.
In such cases, the most likely malfunction of the LED backlight elements. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect the probes in the forward direction to it (red probe to the anode, black to the cathode). In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- 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 PE1091 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). Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Checking or replacing elements MSD8881, K4B2G1646E, K4B1G1446G, TAS5708 requires the necessary training and professional skills in repairing modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by warming up.
Before replacing the TDSS-G224D & TSU25-E02 tuner, if there is no tuning for the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus
Attention TV owners! Attempts at self-repair of the TOSHIBA 40TL968 are not recommended by the manufacturer and can lead to serious negative consequences!


FIRMWARE FOR SPI FLASH  ----------->   TOSHIBA 40TL968, Main: PE1091 V28A001434C1, Panel: LTA400HV04



 The appearance of MainBoard PE1091 is shown in the figure below:
PE1091
PE1091 can be used in TVs:
TOSHIBA 40TL968 (Panel LTA400HV04), TOSHIBA 40TL938 40TL938G (Panel V400NK2-LS5).
The appearance of the power supply
Main features of the TOSHIBA 40TL968 device:
Installed matrix (LED-panel) LTA400HV04.
The matrix control uses the Timing Controller (T-CON) 12PSQBC4LV0.0.
To power the backlight LEDs, a converter is used, combined with the power supply, it is controlled by the SSL110SN PWM controller.
The necessary supply voltages for all nodes of the TOSHIBA 40TL968 TV are generated by the power module N150A002L, or its analogs using microchips A6069, FAN6961 (PFC), L6577B and power switches of the type K12A50D.
MainBoard - the main board (motherboard) is a PE1091 module, using microchips MSD8881, K4B2G1646E, K4B1G1446G, TAS5708 and others.
The TDSS-G224D & TSU25-E02 tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTA400HV04
Type: a-Si TFT-LCD, Panel
Diagonal size: 40 inch
Resolution: 1920x1080, FHD
Display Mode: S-PVA, Normally Black, Transmissive
Active Area: 885.6x498.15 mm
Surface: Antiglare (Haze 2%)
Brightness: 400 cd / m²
Contrast Ratio: 5000: 1
Display Colors: 1.07B (8-bit + Hi-FRC), CIE1931 70%
Response Time: 8 (Max.) (G to G)
Frequency: 120Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (4 ch, 10-bit), 92 pins
Voltage: 12.0V


 Trademark: TOSHIBA, Model: 40TL968.
Briefly from the TV: LCD, LED backlight, 40 ", 1920x1080, 1080p Full HD, 3D, DVR, there is a satellite tuner, sound: 20W, HDMI: 4, Internet access, Wi-Fi, Smart TV.
The Toshiba official website has firmware (software update) for the 40TL968G (7.0.28.16.1), 40TL968B (7.0.27.8.1) models.
The composition uses MainBoard PE1091 V28A001434C1 and an LCD panel (matrix) LTA400HV04.
Power Supply Unit (PSU) N150A002L N11-150P1A Power Supply.
TOSHIBA 40TL968 LED TV with LTA400HV04 LCD, 40 "(102 cm) diagonal display in 16: 9 format. The required screen brightness of 400 cd / m² is provided by LED backlighting. Dynamic contrast ratio of 1,000,000: 1 is achieved by special control of the LEDs. V This model uses side lighting from Edge LEDs.
There is support for 3D images with active (shutter) technology for separating the right and left channels. The design and technical capabilities of the TV include watching programs and movies in high quality HD at a resolution of 1920x1080 pixels in a graphical decomposition according to the standard 1080p (Full HD).
The 40TL968 is equipped with SMART software, integrated applications and the ability to work on the Internet. Connecting to the Internet can be done via Wi-Fi. The input high-frequency or video signal can be processed in analogue systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, MPEG4, DivX, MKV, JPEG.
The power of the acoustic system of sound 20 W (2x10 W) provide 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, component, SCART, VGA, HDMI x4, USB x2, Ethernet (RJ-45), Wi-Fi. An output for connecting headphones is provided. 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, 1280x1024, 1360x768, 1920x1080.
The digital tuner is capable of receiving television channels in the standards DVB-T MPEG4, DVB-C, DVB-T2, DVB-S2.
The power consumed by the TV in the operating mode from the network is 123 watts.
Overall dimensions: with stand 923x613x215 mm, without stand 923x555x56 mm.
TV Weight: with stand: 14.5 kg, without stand: 12.5 kg.
Attention! The TOSHIBA 40TL968 LED TV panel LTA400HV04 is an expensive and unreliable element.
Avoid any impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also unsafe to get liquid on the screen. Sometimes one drop is enough if it flows down the glass onto the cables so that the TV becomes unrepairable.