Tuesday, 31 March 2020

REPAIR / SERVICING TV TOSHIBA 19DL834R

Technical description and composition of the TOSHIBA 19DL834R TV, type of panel and applicable modules. The composition of the modules.
TOSHIBA LED
Model: 19DL834R
Chassis / Version: 17MB
Panel: V185B1-LE2 30070337
LED driver (backlight): 17CON07-2 120111 Vestel
Power Supply (PSU): 17PW05-03 75024747 20551413
PWM Power: G1115LOP (8), ICE3BR0665 (Standby)
MainBoard: 17MB60-3.1 75026094 20563033
IC MainBoard: DVD SA5888, MT1389DE
Tuner: DTOS403LH122E
Control: CT-8023 75026257 20548798
Specifications 19DL834
TOSHIBA 19DL834R
General repair guidelines for TV LCD LED
Diagnostics of malfunctions and repairs of the TOSHIBA 19DL834R, as well as other electronic devices, is recommended to begin with an external inspection of the external and internal elements. Visible damage to elements can sometimes indicate the direction of the search for a defect even before the necessary measurements are taken. 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.
If the 19DL834R TV does not turn on, does not make any sounds when it is turned on, and also no indicators on the front panel light or blink - there is a high probability of a malfunction in the power module. In some cases, only the regulator or power converter of the control processor may be faulty, which is typical for some TOSHIBA models. It is advisable to start the troubleshooting of the power supply module by checking the state of the electrolytic capacitors of the rectifier filters and the mains fuse. Defective capacitors should be replaced. If the mains fuse is broken, it is necessary to check first of all the power semiconductor elements - rectifier diodes and transistors, which are often found in such a state of breakdown.
In most cases, key breakdowns in switching power supplies (SMPS) do not occur for no reason and you should look for other faulty circuit elements that could provoke a defect. This can be dried electrolytic capacitors in the primary circuit, and faulty damper elements, as well as dangling resistors or punched semiconductor elements in the stabilization circuits. Possible defective PWM G1115LOP (8), ICE3BR065 (8) from the manufacturer.
If the TOSHIBA 19DL834R does not have an image, but there is sound and the TV is controlled by the remote control, there may be a malfunction in the backlight circuits of the V185B1-LE2, 30070337. The LEDs or the power converter, the LED driver, may be malfunctioning. 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 LED driver, and check the LEDs, connecting obviously known good diagnostics.
To check the health of the LEDs, as well as contact connections in the ruler circuit, it is necessary to disassemble the panel.
To detect a break in the LED lines without disassembling the panel, a current source is required. It is impossible to open transitions connected in series with a simple multimeter; voltage of several tens of volts is necessary.
On the motherboard 17MB60-3.1 75026094 20563033, in the event of a malfunction, you should first check the performance of all the stabilizers or power converters of the microcircuits and, if necessary, update the software (software).
When repairing an MB board, you need to check its components DVD SA5888, MT1389DE. Defective items should be replaced. If BGA chips are installed, their malfunction is usually localized by heating. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
Before replacing the DTOS403LH122E tuner, if there is no tuning for the channels, you must first check the power supply voltage at its terminals, including the power supply of varicaps (30-33V).
Attention to the owners! Attempts to self-repair the TOSHIBA 19DL834R TV are not recommended by the manufacturer and can lead to serious negative consequences!


SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    TOSHIBA 19DL833R, 19DL834R. Main VESTEL 17MB60

 The appearance of the MainBoard 17MB60-3.1 is shown in the figure below:
The 17MB60-3.1 motherboard is made using the MSD9WB7PX-2 processor, combined with a scaler. For its work, two microchips of external random access memory (DDR) HY5PS121621C and read-only memory (ROM) NAND512-A are used. To ensure processor power, stabilizers 1.2V, 2.5V, 3.3V are used. For DDR, the voltage is 1.8V, for the power of NAND 3.3V. It is advisable to start the repair by checking the power supply of the standby mode 3.3V. Further, in the operating mode, it is necessary to check the operability of all linear stabilizers and voltage converters. If there is a backlight and no image, the power of the LCD panel 5V or 12V, depending on the type of panel used, can be measured directly on the LVDS connector. A typical malfunction is a NAND ROM software failure. At the same time, the TV does not turn on and the indicators on the panel blink. It is updated via the USB port if the software of the SPI FLASH chip in which the bootloader is located is not damaged, or if there is a mboot.bin file on the media, which can be used as standard SPI FLASH content.
17MB60-3.1 can be used in TVs:
TOSHIBA 19DL834R (Panel V185B1-LE2 30070337), TOSHIBA 22DL833R 22DL834R (Panel LC216EXN (SD)(A1)), TOSHIBA 22EL833R (Panel LC216EXN-SDA1 / LC216EXN-SCA1), TOSHIBA 26DL834R (Panel LC260EXN (SD)(A3)), TOSHIBA 19DL833R (Panel V185B1-LE2 REV. C1).
Main features of the TOSHIBA 19DL834R device:
Installed matrix (LED panel) V185B1-LE2 30070337.
The LED driver 17CON07-2 is used to power the backlight LEDs.
The necessary supply voltages for all nodes of the TOSHIBA 19DL834R TV are generated by the 17PW05-03 power supply module or its analogs using G1115LOP (8), ICE3BR0665 (Standby) microcircuits.
MainBoard - the main board (motherboard) is a 17MB60-3.1 module, using DVD chips SA5888, MT1389DE and others.
The DTOS403LH122E tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: V185B1-LE2
Type: a-Si TFT-LCD, Panel
Diagonal size: 18.5 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 409.8x230.4 mm
Surface: Antiglare (Haze 25%), Hard coating (3H)
Brightness: 250 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit), CIE1931 70%
Response Time: 1.3 / 3.7 (Tr / Td)
Frequency: 60Hz
Lamp Type: 14S8P WLED Without Driver
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V
 Brand: TOSHIBA, Model: 19DL834.
Briefly from the TV: LCD, LED backlight, built-in DVD player, 19 ", 1366x768, 720p HD, sound: 5W, HDMI connectors: 2.
The composition uses MainBoard 17MB60-3.1 75026094 and an LCD panel (matrix) V185B1-LE2.
Power Supply Unit (PSU) 17PW05-03 75024747 Power Supply.
TOSHIBA 19DL834 LED TV with V185B1-LE2 LCD, 19 "(48 cm) diagonal, 16: 9 format. The required screen brightness of 300 cd / m² is provided by LED backlighting. The ratio of maximum brightness to minimum (contrast) is 1000 : 1. Dynamic contrast ratio of 3,000,000: 1 is achieved by special control of the LEDs. This model uses side LED backlighting from Edge LEDs. You can view images in high quality HD at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). 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, Xvid, DivX , MKV, VideoCD, SVCD, Picture CD, JPEG.
The power of the speaker system of sound 5 W (2x2.5 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, RGB, VGA, HDMI x2, USB. 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.
A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C standards.
The power consumed by the TV in the operating mode from the network is 20 watts.
Overall dimensions: with stand 462x337x159 mm, without stand 462x302x54 mm.
TV Weight: with stand: 4.1 kg, without stand: 3.8 kg.
Attention! The V185B1-LE2 panel of a TOSHIBA 19DL834 LED TV 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.