Friday 27 December 2019

REPAIRING / SERVICING TV SAMSUNG LE40C550J1W

Technical description and composition of the SAMSUNG LE40C550J1W TV, panel type and applicable modules. The composition of the modules.
SAMSUNG
Model: LE40C550J1W LE40C550J1
Chassis / Version: N82A
Panel: LTF400HM01
T-CON: F60MB4C2LV0.6; LAU4041X1A-Q MAX9591, MAX17122, MAX17121E, 24C64WP
Inverter (backlight): SSB400_12V01 LJ97-02591A
PWM Inverter: LX6503, LM393F
MOSFET Inverter: 780N09C6S
Power Supply (PSU): BN44-00340B
PWM Power: FAN7530 (PFC), LX6503AID, A393F, STR-W6052S
MOSFET Power: K8A50D, R5009FNX, F10UP60S, AO4606
MainBoard: BN41-01331B - BN94-03391K
IC MainBoard: SETD-70, ATMLH004 2EB1, ATMLH002 02B1, 25L4005AM2C, K4T1G1640E-HCF8, STA369BWS, DRV604, SiI9287BCNU
Tuner: BN40-00173A DTOS40CVL081A
Specifications LE40C550
SAMSUNG LE40C550J1W
General repair guidelines for TV LCD
Repair and diagnostics of any electronic device, in particular SAMSUNG LE40C550J1W LE40C550J1, it is advisable to start with a careful external examination of internal and external elements. According to some external signs of a change in the state of some elements, it is sometimes possible to make assumptions about the nature of the defect, as well as determine the further direction of the troubleshooting. Experienced repairmen are well aware of what ring cracks look like in soldered terminals, swollen capacitors, and other causes of problems in electronic devices.
If the LE40C550J1W does not turn on, does not respond to the remote control and the front panel buttons, does not blink light bulbs and does not show any signs of operability, the BN44-00340B power supply module is probably faulty in this case. When repairing the power supply, it is advisable to start the diagnostics by checking the mains fuse and the electrolytic capacitors of the filters of the converter secondary rectifiers. In the event of a fuse breaking, the reason should be sought in the power semiconductor elements of the pulse converter of the main power supply. First of all, it is necessary to check the diodes of the bridge of the rectifier of the mains voltage and the power key (s) of the K8A50D, R5009FNX, F10UP60S, AO4606 converter.The complete inoperability of the power supply unit can be caused by a short circuit of the power elements in the primary circuit, followed by an open fuse, or a short circuit in the loads.
The reasons for the breakdown of the power switch in pulsed power supplies (IIPS) can be different, for example, a malfunction of semiconductor cells or electrolytic capacitors in the stabilization circuits of the primary circuit, as well as a failure in the operation of the FAN7530, LX6503AID, A393F, STRW6052S PWM controller, or broken resistors in its harness.
If, when you turn on the TV, the image appears and immediately disappears, or is absent initially when you turn on, but there is sound and other functions work, there is a high probability of a malfunction of the inverter (power converter of the backlight). In such cases, the lamps, the inverter and the common power module are subject to verification, in which the electrolytic capacitors of the rectifier filter supplying the inverter should be checked. When disabling protection in order to enable the diagnosis of a malfunction, special care should be taken, and after completion of all repair work, it is necessary to restore the circuit and the inverter protection for further safe operation of the TV.
Repair or diagnostics of the motherboard BN41-01331B - BN94-03391K should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update the software (software). Board repair and replacement of chips SETD-70, ATMLH004 2EB1, ATMLH002 02B1, 25L4005AM2C, K4T1G1640E-HCF8, STA369BWS, DRV604, SiI9287BCNU are carried out with the necessary equipment, and the corresponding element base. Faults associated with the application of BGA processor soldering technologies can be localized by the heating method.
Before replacing the BN40-00173A DTOS40CVL081A tuner, if there is no tuning for the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus
Owners and users of the SAMSUNG LE40C550J1W TV must remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!


SCHEMATICS ------->  Samsung Chassis N82A.

FOR MODELS -----------> Samsung LE32C53***, LE37C53***, LE40C53***, LE46C53***, LE32C57***, LE37C57***, LE40C57***, LE46C57***, LE32C55***, LE37C55***, LE40C55***, LE46C55***, LE26C45***, LE32C45***

PSU SCHEMATIC----------> BN44-00340B Power Supply schematic diagram.



 The appearance of the MainBoard BN41-01331B is shown in the figure below:
BN41-01331B
BN41-01331B can be used in TVs:
SAMSUNG LA32C450 (Panel LFT320AP08), SAMSUNG LA32C450E1D (Panel LTF320AP08 A10), SAMSUNG LE26C450E1WXRU (Panel LTF260AP04), SAMSUNG LE32C530F1 LE32C53051F5W5405L Panel, LTF320HMF150, SAML5505F150, Panel LTF320HMF150
PSU Advanced
The LE40C550J1W TV is equipped with a BN44-00340B power module using the PFC (Power Factor Correction) scheme acting as an active filter to eliminate the higher harmonic components of the current consumption. The boost converter based on the FAN7530 PWM controller does not allow the electrolytic capacitor of the input rectifier filter to be connected to the network directly through open diodes, when the reactance (about 15-30 ohms at a frequency of 50 Hz) determines the charge current. As a result of the conversion, the charging current of the capacitor will be determined in such a way that the envelope of the high-frequency pulses of the input current will repeat the phase and shape of the sine wave of the input voltage. The health check of the PFC unit is carried out by measuring the DC voltage on the capacitor of the rectifier network. In operating mode, it should be around 380V, in standby approximately 300V.
The appearance of the power supply
Main features of the SAMSUNG LE40C550J1W device:
Installed matrix (LCD panel) LTF400HM01.
The matrix control uses the Timing Controller (T-CON) F60MB4C2LV0.6 ;.
To power the backlight, an inverter SSB400_12V01 is used, it is controlled by the PWM controller LX6503, LM393F. As power elements of the inverter, keys of the type 780N09C6S are used.
The necessary supply voltages for all nodes of the TV SAMSUNG LE40C550J1W are generated by the power module BN44-00340B, or its analogs using microchips FAN7530 (PFC), LX6503AID, A393F, STR-W6052S and power switches such as K8A50D, R5009FNX, F10UP606S, AO4.
MainBoard - the main board (motherboard) is a BN41-01331B module, using the chips SETD-70, ATMLH004 2EB1, ATMLH002 02B1, 25L4005AM2C, K4T1G1640E-HCF8, STA369BWS, DRV604, SiI9287BCNU and others.
The tuner BN40-00173A DTOS40CVL081A provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTF400HM01
Type: a-Si TFT-LCD, Panel
Diagonal size: 40 inch
Resolution: 1920x1080, FHD
Display Mode: S-PVA, Normally Black, Transmissive
Frequency: 60Hz
Lamp Type: WLED