Wednesday 25 March 2020

REPAIR / SERVICING TV BBK LEM3279F

Technical description and composition of the BBK LEM3279F TV, panel type and applicable modules. The composition of the modules.
BBK LED
Model: LEM3279F
Panel: T320HVN01.2 / SEL320V8-S0JB
LED driver (backlight): 168P-P32EWM-WB
Power Supply (PSU): 168P-P32EWM-WB
PWM Power: TEA1733 (8)
MainBoard: E182VG-Z0-A0
IC MainBoard: MST6M18VGC-LF-Z, IT6633E-P, MSH9010-LF
Tuner: R620D
Technical Specifications LEM3279F
BBK LEM3279F
General repair guidelines for TV LCD LED
Possible malfunctions
- The BBK LEM3279F TV does not turn on at all. There is no reaction to the remote control or to the control buttons from the front panel. Indicator lights do not light or flash.
In such cases, the fault should be sought first in the 168P-P32EWM-WB power supply module. It is necessary to measure its secondary output voltages, and in case of their absence, check the serviceability of the power switches of the converters and rectifier diodes for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during a short circuit in the elements of the primary circuit, the mains fuse usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power supply, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. PWM chip TEA1733 (8) can also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, there is sound, it reacts to the remote control, channels are switched. In some cases, the image appears when you turn on and immediately disappears.
As a rule, in such cases there is no display backlight. 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.
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 TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the E182VG-Z0-A0 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). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the elements MST6M18VGC-LF-Z, IT6633E-P, MSH9010-LF. BGA chip malfunctions are usually easy to detect by warming up.
If you suspect a malfunction of the R620D tuner, first of all, it is necessary to verify the correctness of the software, as well as the presence of the necessary voltage levels and impulses of data exchange with the processor via the I2C bus at the corresponding terminals of the tuner.
We recommend the owners of the LEM3279F TV for repair only to qualified specialists with the necessary work experience! Self-repair attempts without the appropriate knowledge and skills can lead to irreversible negative consequences!


SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    LEM3279, LEM3289, LEM3279F, LEM3289F, LEM4079F, LEM4289F, LEM4289F

Service Manual with Schematic Diagram 58 pages of 2012 on the LEM3279, LEM3289, LEM3279F, LEM3289F, LEM4079F, LEM4289F, LEM4289F models

 The appearance of the MainBoard E182VG-Z0-A0 is shown in the figure below:
E182VG-Z0-A0
E182VG-Z0-A0 can be used in TVs:
BBK LEM3279F (Panel T320HVN01.2 / SEL320V8-S0JB), BBK LEM4079F (Panel SEL390V7-S00E (WXGA)), BBK LEM4279F (Panel SEL420V6-S00E Rev.R1 PCB:C3 LED:S442), BBK LEM4289F (Panel SEL420V6-S00E).
Main features of the BBK LEM3279F device:
The matrix (LED panel) T320HVN01.2 / SEL320V8-S0JB is installed.
The LED driver 168P-P32EWM-WB is used to power the backlight LEDs.
The necessary supply voltages for all nodes of the BBK LEM3279F TV are generated by the 168P-P32EWM-WB power module or its analogs using TEA1733 microcircuits (8).
MainBoard - the main board (motherboard) is an E182VG-Z0-A0 module, using microchips MST6M18VGC-LF-Z, IT6633E-P, MSH9010-LF and others.
The R620D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: T320HVN01.2
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1920x1080, FHD
Display Mode: AMVA, Normally Black, Transmissive
Active Area: 698.4x392.85 mm
Surface: Antiglare (Haze 2%), Hard coating (3H)
Brightness: 350 cd / m²
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 6.5 (G to G)
Frequency: 60Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V


 BBK LEM3279F LED TV with T320HVN01.2 LCD, 32 "(81 cm) diagonal size in 16: 9 format. The required screen brightness of 350 cd / m² is provided by LED backlighting. The ratio of maximum brightness to minimum (contrast) is 4000 : 1. This model uses Edge LED backlighting, and the design and technical features of the TV include watching broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphic resolution according to the standard 1080p (Full HD). 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, JPEG. Stereo audio is realized by two built-in 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, SCART, VGA, HDMI x3, 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, 1360x768.
Overall dimensions: With stand 461x338x156 mm, Without stand 461x302x51 mm.
TV Weight: 10.3 kg.
Attention! The T320HVN01.2 / SEL320V8-S0JB panel of the BBK LEM3279F 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.