Saturday 28 December 2019

REPAIRING / SERVICING TV SAMSUNG LE40M51BS

Technical description and composition of the SAMSUNG LE40M51BS TV, panel type and applicable modules. The composition of the modules.
SAMSUNG
Model: LE40M51BS LE40M51B
Panel: LTA400W2-L01
Lamp backlight: 20 Lamp CCFL
T-CON: 400W2C4LTV0.1
Inverter (backlight): 24V40W2S HIP0212A
PWM Inverter: DMB8110D
MOSFET Inverter: SI4942
Power Supply (PSU): BN41-00521B
PWM Power: VIPER12ADIP, ICE1PCS02, STR-W6755
MOSFET Power: 20N60
MainBoard: BN41-00630B
IC MainBoard: MSP4410K B3, M30620SP, MST9883CR-LF, SIL9993CTG100
Tuner: BN40-00051A TMQZ6-404C
Technical specifications LE40M51BS
SAMSUNG LE40M51BS
General repair guidelines for TV LCD
Possible malfunctions
- The SAMSUNG LE40M51BS TV does not turn on, does not respond to the remote control and buttons on the control panel, does not light up or blink indicators.
Usually with such manifestations, the defect is caused by faulty elements in the main power module BN41-00521B. It is then necessary to measure its output voltages and, if they are absent, you should check the power switches (20N60) and the rectifier diodes of the converters for the probability of a short circuit.
In case of breakdowns in the secondary circuits, the converter, as a rule, can emergency work in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM) VIPER12ADIP, ICE1PCS02, STR-W6755, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, there is sound, it responds to the remote. Or the image may appear for a second when turned on and immediately disappears.
These manifestations can be triggered by a power supply module, or by inverter defects, as well as distortion of the currents in the lamps due to their uneven wear. After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, it is necessary to ring in its converter the power switches for breakdown and the secondary windings of transformers for an open.
Sometimes, for diagnostic purposes, inverter protection must be disabled. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- The TV does not turn on, the indicator signals standby or working mode, or blinks.
Repair or diagnostics of the BN41-00630B 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 chips MSP4410K B3, M30620SP, MST9883CR-LF, SIL 9993CTG100 and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
In cases where there is no 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 voltages at the terminals of the tuner BN40-00051A. It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
Attention TV owners! Attempts to self-repair SAMSUNG LE40M51BS are not recommended by the manufacturer and can lead to serious negative consequences!

SCHEMATIC Samsung-------->  BN41-00521B Power supply


The appearance of the MainBoard BN41-00630B is shown in the figure below:
BN41-00630B
BN41-00630B can be used in TVs:
SAMSUNG LE40M51BS LE40M51B (Panel LTA400W2-L01), SAMSUNG LE32M51BS (Panel LTA320W2-L14).
The appearance of the power supply
Main features of the SAMSUNG LE40M51BS device:
Installed matrix (LCD-panel) LTA400W2-L01.
The matrix control uses the Timing Controller (T-CON) 400W2C4LTV0.1.
To power the backlight, an inverter 24V40W2S is used, it is controlled by the PWM controller DMB8110D. As power elements of the inverter, keys of type SI4942 are used.
The necessary supply voltages for all nodes of the SAMSUNG LE40M51BS TV are generated by the BN41-00521B power module or its analogs using VIPER12ADIP, ICE1PCS02, STR-W6755 microcircuits and 20N60 type power switches.
MainBoard - the main board (motherboard) is a BN41-00630B module, using microchips MSP4410K B3, M30620SP, MST9883CR-LF, SIL9993CTG100 and others.
The tuner BN40-00051A TMQZ6-404C provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTA400W2-L01
Type: a-Si TFT-LCD, Panel
Diagonal size: 40 inch
Resolution: 1366x768, WXGA
Display Mode: PVA, Normally Black, Transmissive
Active Area: 885.168x497.664 mm
Surface: Antiglare (Haze 44%), Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 800: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 10/6 (Tr / Td)
Frequency: 60Hz
Lamp Type: 20 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V