Thursday 26 March 2020

REPAIR / SERVICING TV TOSHIBA 19SLDT2

Technical description and composition of the TOSHIBA 19SLDT2 TV, type of panel and applicable modules. The composition of the modules.
Toshiba
Model: 19SLDT2
Chassis / Version: CMG130A
Panel: M190A1-L0A C1
PWM Inverter: LM2902 (14)
Power Supply (PSU): PCB240 AE009798 A51K01A240 CEG362A
MainBoard: CMG130A
IC MainBoard: CPU: VST6973G B3 000; EEPROM: M24256;
Tuner: TDTG-S486D
Control: PCBDA0 AE009801 A51K01ADA0 REMOCON PCB ASS'Y CEG364A
Specifications 19SLDT2
TOSHIBA 19SLDT2
General recommendations for repairing TV LCD
Any repair of electronic equipment begins with an external inspection of the device and diagnosis of the malfunction. In this case, you should visually carefully examine all the elements of the TOSHIBA 19SLDT2 TV, both internal and external. Often, according to certain external signs, the repairman can draw some conclusions about the reasons for the failure of certain elements of the circuit even before the necessary measurements are made, which will determine the further algorithm for troubleshooting and localizing the defect. In some cases, faulty elements can be seen with the naked eye, for example, charred resistors or swollen metal-ceramic capacitors, or electrolytic in rectifier filters. Ring cracks formed in the soldered terminals of transformers or heating elements of the circuit are also frequent sources of many malfunctions with a variety of external manifestations.
In the case when 19SLDT2 does not turn on, does not respond to the remote control and buttons on the front panel, does not blink bulbs and does not show any signs of operability, most likely in this case the PCB240 AE009798 A51K01A240 POWER PCB ASS'Y CEG362A power supply module is faulty. In this case, the diagnosis and repair of the common power supply should always be started by checking the mains fuse. When it breaks, it is advisable to check for a breakdown, first of all, all power semiconductor elements of the converter and the rectifier diode bridge of the network, as well as the large electrolytic capacitor of the filter of the network rectifier and the key transistor.
If a breakdown of the power switch of the flyback converter of the power supply unit is detected, it should be remembered that it does not fail without any reasons that should be sought by checking other elements of the primary circuit - electrolytic capacitors, a PWM controller that can only be checked by replacement, as well as others semiconductor elements (diodes, transistors, zener diodes).
When using a power factor correction unit (PFC) in the power modules, troubleshooting becomes somewhat more complicated and requires additional experience and knowledge of their operation.
If the TOSHIBA 19SLDT2 does not have an image, but there is sound and the TV is controlled by the remote control, a malfunction in the display backlight nodes is likely. The lamps or the power converter - inverter may be faulty. Often in such cases, when you turn on the TV, an image appears and immediately disappears. First of all, it is necessary to verify the operability of the electrolytic capacitors of the rectifier filter supplying the inverter, and check the LCD lamps by connecting external and obviously serviceable for diagnosis to the connectors.
Diagnosis and repair of the inverter is often complicated by the organization of special protection circuits, which is necessary for fire safety and turns off the inverter in any emergency situation, for example, when the lamps are worn or depressurized. Often, to localize a defect, its blocking is required.
In these cases, special care must be taken in view of the risk of failure of the power elements. After completing all repair work, it is imperative to restore the protection circuits for full and safe further operation of the TV by the user.
In cases where there is no tuning to the local television channels, you should make sure that there is a varicap supply voltage (30-33V) and other supply voltages at the terminals of the TDTG-S486D tuner.
Owners and users of the TOSHIBA 19SLDT2 TV must 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!


SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    Toshiba 15/19/22/SLDT2 CMG130A

 The appearance of the MainBoard CMG130A is shown in the figure below:
CMG130A
CMG130A can be used in TVs:
TOSHIBA 15SLDT2 (Panel CLAA150XP07FQ (V7201) AE009749 09EK115007), TOSHIBA 19SLDT2 (Panel M190A1-L0A C1), TOSHIBA 22SLDT2 (Panel T220SW01 V.0 AE009667).
Main features of the TOSHIBA 19SLDT2 device:
Installed matrix (LCD panel) M190A1-L0A C1.
A converter controlled by the LM2902 PWM controller (14) is used to power the backlight lamps.
The formation of the necessary supply voltages for all nodes of the TOSHIBA 19SLDT2 TV is carried out by the PCB240 power module, or its analogues.
MainBoard - the main board (motherboard) is a CMG130A module using CPU chips: VST6973G B3 000; EEPROM: M24256; and others.
The TDTG-S486D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: CMO
Model: M190A1-L0A
Type: a-Si TFT-LCD, Panel
Diagonal size: 19.0 inch
Resolution: 1440x900, WXGA +
Display Mode: TN, Normally White, Transmissive
Active Area: 408.24x255.15 mm
Surface: Antiglare (Haze 25%), Hard coating (3H)
Brightness: 300 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 72%
Response Time: 1.5 / 3.5 (Tr / Td)
Frequency: 60Hz
Lamp Type: 4 pcs CCFL Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 30 pins
Voltage: 5.0V

 TOSHIBA 19SLDT2 LCD TV with M190A1-L0A LCD, 19 "(48 cm) diagonal 16:10 format. 300 cd / m² screen brightness is provided by CCFL (EEFL) fluorescent lamps. Maximum brightness to minimum ratio (contrast) ) is 1000: 1. The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i, 576p. Supported media file formats: MP3, WMA, MPEG4, VideoCD, SVCD, JPEG.
The power of the speaker system is 3 W (2x1.5 W). It uses a NICAM stereo signal processing system and Sound Surround.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), SCART, RGB, VGA. 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.
The power consumed by the TV in the operating mode from the network is 55 watts.
Overall dimensions: with stand 472x401x207 mm, without stand 472x364x67 mm.
TV Weight: with stand: 6.8 kg, without stand: 5.1 kg.
Attention! The M190A1-L0A C1 panel of the TOSHIBA 19SLDT2 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!