Friday, 21 August 2020

REPAIRING / SERVICING TV DNS E16A90

Technical description and composition of the DNS E16A90 TV, panel type and modules used. The composition of the modules.
DNS LED
Model: E16A90
Chassis / Version: T.MS18VG.62B11505
Panel: LP156WH4 (TL) (A1)
LED backlight: EDGE LED 4 strings
LED driver (backlight): integrated into T-Con 4 strings
MainBoard: T.MS18VG.62B 11505
IC MainBoard: CPU: MST6M181VG, SPI FLASH: 25Q32BA, AUDIO: YD1517P
Tuner: LP156WH4 (TL) (A1)
E16A90 Specifications
DNS E16A90
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- DNS E16A90 TV does not turn on. There are no signs of operability. The indicators on the front panel do not light or blink, the TV does not respond to the remote control and control buttons.
Most likely in this case, the main switching power supply (SMPS) is faulty. Then you should measure its output voltages and, in case of their complete or partial absence, it is necessary to check the serviceability of the power switches and rectifier diodes of the converters for a possible short circuit.
In the event of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse and / or the current sensor in the source of the key usually breaks off.
Breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM), if they do not have visible damage to the case and an outright short circuit between the terminals, are usually checked by replacement.
- There is no picture, but there is sound, it reacts to the remote control. Or the image appears when turned on and disappears immediately
Often in such cases, there is no backlighting of the LED panel. The reason may 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.
To check the health of the LED circuit, it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED separately with a simple Chinese multimeter (powered by 9 volts) in the P-N transition test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black one to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. The serviceability of the PN junction of the Zener diode indirectly indicates the serviceability of the LED-a
- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.
Repair or diagnostics of the T.MS18VG.62B motherboard should begin with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In cases of complex MB (SSB) repairs and with the necessary skills and equipment, it may sometimes be necessary to replace its chips CPU: MST6M181VG, SPI FLASH: 25Q32BA, AUDIO: YD1517P and other possible faulty components. Malfunctions associated with the use of BGA soldering technologies are usually easily diagnosed by the warm-up method.
If you suspect a malfunction of the LP156WH4 (TL) (A1) tuner, first of all, you need to make sure the software is correct, as well as the presence of the required supply voltage levels and data exchange pulses with the processor via the I2C bus on the corresponding tuner pins.
Once again, we remind TV users: you should not try to repair yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repairs to professionals with sufficient experience in the field of electronic repair.

DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   DNS E16A90, Main: T.MS18VG.62B 11505, Panel: LP156WH4 (TL)(A1)


 The appearance of the MainBoard T.MS18VG.62B is shown in the figure below:
T.MS18VG.62B
T.MS18VG.62B can be used in TVs:
BBK LEM2483F (Panel LG LC 230EUE(TD)(A1)), BBK LEM1983 (Panel LM185WH2 (TL)(A1)), DNS M24AM2 (Panel M236HGE-P02), DNS E16A90 (Panel LP156WH4 (TL)(A1)), ERISSON 23LEN60 (Panel LM230WF5), ERISSON 22LEN60 (Panel LS215AFTNO), ERISSON 24LEN60 (Panel LM230WF5 ), ERISSON 15LEN60 (Panel B156XW02 V.2), IZUMI TLE22F750B (Panel M215HGE-L10), RUBIN RB-19S2U (Panel V185B1-PE1 A01 REV 1.0), SUPRA STV-LC18250FL (Panel B173RW01 V.3).
Main features of the DNS E16A90 device:
Installed matrix (LED-panel) LP156WH4 (TL) (A1).
The integrated LED driver is used to power the backlight LEDs.
The required supply voltages for all nodes of the DNS E16A90 TV are provided by a switching power supply.
MainBoard - the main board (motherboard) is a T.MS18VG.62B module, using CPU chips: MST6M181VG, SPI FLASH: 25Q32BA, AUDIO: YD1517P and others.
The LP156WH4 (TL) (A1) tuner provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LP156WH4-TLA1 61 Compatible model
Type: a-Si TFT-LCD, Panel
Diagonal size: 15.6 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 344.232x193.536 mm
Shape Style: Wedge (PCBA Bent, Depth? 5.2mm)
Surface: Glare (Haze 0%), Hard coating (3H)
Brightness: 220 cd / m²
Contrast Ratio: 400: 1
Display Colors: 262K (6-bit), CIE1931 60%
Response Time: 16 (Tr + Td)
Frequency: 60Hz
Lamp Type: 4 strings WLED Embedded (LED Driver)
Signal Interface: LVDS (1 ch, 6-bit), 40 pins
Voltage: 3.3V
DNS E16A90 TV with LCD LP156WH4, diagonal size 16 "(41 cm) 16: 9 format. The required screen brightness of 220 cd / m² is provided by LED backlighting. Contrast - the ratio of maximum brightness to minimum is 1000: 1. Dynamic contrast ratio 30,000: 1 is achieved by special control of the LEDs depending on the illumination of the areas in the scene.This model uses a panel with an edge arrangement of backlight LEDs - Edge LED.
LP156WH4 (TL) (A1) sensor and MainBoard T.MS18VG.62B software provide high quality HD image viewing at 1366x768 pixels in 720p (HD Ready). The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Graphic processing and formation of a digital signal occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i. Supported media file formats: MP3, MKV, JPEG.
Speaker power of 6 W (2x3 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, SCART, VGA, HDMI, USB. A headphone output is provided. To connect a computer or laptop to this TV model, use the VGA (D-Sub 15) connector on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080.
The power consumed by the TV operating in mains mode is 24 W.
Overall dimensions: 394x304x126 mm.
TV weight: 1.6 kg.
Attention! The LP156WH4 (TL) (A1) panel of the DNS E16A90 LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.