Thursday, 16 January 2020

REPAIR / SERVICING TV SAMSUNG UE46B7050WW

Technical description and composition of the SAMSUNG UE46B7050WW TV, panel type and applicable modules. The composition of the modules.
SAMSUNG LED
Model: UE46B7050WW UE46B7050
Chassis / Version: UE46B7050WWXXE
Panel: LTF460HF08
LED backlight: SVS46 2ND 120HZ 01/09/30
LED driver (backlight): integrated into PSU
Power Supply (PSU): BN44-00269A PD4612F1 PSLF171B01A
PWM Power: MC33067P
MainBoard: BN41-01190B BN94-02706N
IC MainBoard: WM8593SEFT, RTL8100CSL, K4T1G164QE-HCE7
Tuner: BN40-00145B
Control: Touch Key: BN41-01204A BN96-10736C
Appearance
SAMSUNG UE46B7050WW
General repair guidelines for TV LCD LED
Possible manifestations of defects
- SAMSUNG UE46B7050WW 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.
With similar manifestations, in some cases, the BN44-00269A power module is faulty. 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 breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during 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, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM microcircuits MC33067P are usually checked by replacing with new, or obviously working.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn on and immediately disappears
In some of these cases, a malfunction is caused by a lack of display backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the LED line for breaks without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally, a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters, as a rule, light up a single 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as an indicator of serviceability. In faulty LEDs, the 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 BN41-01190B motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, you should update or replace the software (software). In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its WM8593SEFT, RTL8100CSL, K4T1G164QE-HCE7 chips and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
In the absence of tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltage at the terminals of the tuner BN40-00145B. It is also necessary to check, using an oscilloscope, the presence of pulses of data exchange between the tuner and the processor via the I2C bus.
Attention TV owners! Attempts at self-repair of SAMSUNG UE46B7050WW are not recommended by the manufacturer and can lead to serious negative consequences!

The appearance of the MainBoard BN41-01190B is shown in the figure below:
BN41-01190B
BN41-01190B can be used in TVs:
SAMSUNG UE40B6000VW UE40B6000 (Panel LTF400HF08), SAMSUNG UE46B7000WW UE46B7000 (Panel LTF460HF08), SAMSUNG UE46B6000VW UE46B6000 (Panel LTF460HF08), SAMSUNG UE46B7020 UE46B7020WW (Panel LTF460HF08).
The appearance of the power supply
Main features of the SAMSUNG UE46B7050WW device:
Installed matrix (LED-panel) LTF460HF08.
To power the backlight LEDs, a converter is used, combined with a power supply.
The formation of the necessary supply voltages for all nodes of the SAMSUNG UE46B7050WW TV is carried out by the BN44-00269A power module, or its analogs using MC33067P microcircuits.
MainBoard - the main board (motherboard) is a module BN41-01190B, using microcircuits WM8593SEFT, RTL8100CSL, K4T1G164QE-HCE7 and others.
The tuner BN40-00145B provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTF460HF08
Type: a-Si TFT-LCD, Panel
Diagonal size: 46 inch
Resolution: 1920x1080, FHD
Display Mode: SPVA, Normally Black, Transmissive
Active Area: 1018.08x572.67 mm
Frequency: 60Hz
Lamp Type: CCFL
Signal Interface: LVDS (2 ch, 8-bit)