Saturday, 28 December 2019

REPAIRING / SERVICING TV SAMSUNG LE40R82BX

Technical description and composition of the SAMSUNG LE40R82BX TV, panel type and applicable modules. The composition of the modules.
SAMSUNG
Model: LE40R82BX
Panel: LTA400WT-L07 0T1
T-CON: 4046HDCM4LV0.2
Inverter (backlight): integrated into PSU + SSB400WA16V Rev0.1
PWM Inverter: LX1691A
Power Supply (PSU): BN44-00165A
PWM Power: FSDM0365R (Standby), FAN7382, ICE2BS01, ICE1PCS02 (PFC)
MOSFET Power: 13N50CF, FQPF9N50C, 6N80
MainBoard: BN41-00839E BN94-01441L
IC MainBoard: 7568U-LF, M308AOSGP, EM6A9320BI-4MG, NTP-3000, MAX232EC, 24C256BN
Tuner: HTM2-6L2 / 235S
Technical specifications LE40R82B
SAMSUNG LE40R82BX
General repair guidelines for TV LCD
Repair of the SAMSUNG LE40R82BX TV should begin with a careful external inspection and diagnosis of the malfunction. In this case, it is advisable to carefully examine both internal and external components. Often, based on certain external signs, it is possible to draw some conclusions about the reasons for the failure of certain elements of the circuit even before the necessary measurements are made, which will determine the further algorithm for troubleshooting and localizing the defect. In some cases, faulty elements are visible to the naked eye, for example, charred resistors or swollen metal-ceramic capacitors, or electrolytic in rectifier filters. Ring cracks formed in the soldered terminals of transformers or heating elements of the circuit are also frequent sources of many malfunctions with a variety of external manifestations.
If the SAMSUNG LE40R82BX does not turn on, no control lights on the front panel light up or blink, therefore, there is a very high probability of a BN44-00165A power supply module malfunctioning. When diagnosing and repairing the BN44-00165A power supply, first of all, it is necessary to check the fuse, and if it breaks, the power switch and rectifier bridge diodes should be checked for avalanche (thermal) breakdown.
In most cases, a breakdown of the N-Fet converter key does not occur for no reason and you should look for other faulty circuit elements that could provoke a defect. This can be dried electrolytic capacitors in the primary circuit, and faulty damper elements, as well as dangling resistors or punched semiconductor elements in the stabilization circuits. Possible defective PWM chip from the manufacturer.
Diagnostics of power modules with a Power Factor Corrector (CMC) is somewhat more complicated and requires a more detailed approach.
If the SAMSUNG LE40R82BX TV does not have an image, but there is sound, the malfunction should be sought in the backlight lamp power converter (inverter). It is also necessary to check the serviceability of the electrolytic capacitors of the filter of the secondary rectifiers of the BP (power supply) for an overstated ESR.
Often, attempts to repair the SSB400WA16V Rev0.1 inverter are hampered by the fact that the fault diagnosis is complicated by the operation of its protection, which is designed to turn off the inverter in emergency conditions - when the lamps are depressurized, breaks or short circuits in high-voltage connections and other emergency situations. Lock protection to localize the defect is popular among repairmen.
When diagnosing with the protection off, special precautions must be taken, because there is a risk of failure of the power elements of the inverter. After the diagnosis, it is imperative to restore the protection circuits for the inverter to operate normally.
In cases of attempts to repair the motherboard BN41-00839E BN94-01441L, it is necessary to check the operability of the power supply circuits of the microcircuits and, if possible, update the software (software).
Once again, remind users! Attempts to self-repair a SAMSUNG LE40R82BX TV without the appropriate qualifications and experience can lead to its complete non-repairability!

SCHEMATIC ----------->  32-40R81BX Chassis GBP32-40SEN.

PSU SCHEMATIC ------------->  BN44-00165A.


The appearance of the MainBoard BN41-00839E is shown in the figure below:
BN41-00839E
BN41-00839E can be used in TVs:
SAMSUNG LE32R81B LE32R81W (Panel LTF320AB01), SAMSUNG LE32R81BX (Panel V315B1-L01 Rev. C3), SAMSUNG LE37R82BX LE37R82B (Panel T370XW02 V6), SAMSUNG LE40R82BX (Panel LTA400WTLT. 081, LT40BTWT-L07 081, LT40BTL07
PSU Advanced
The LE40R82BX is equipped with a BN44-00165A power module using the PFC (Power Factor Correction) circuitry acting as an active filter to eliminate the higher harmonic components of the current consumption. The boost converter based on the ICE1PCS02 PWM controller does not allow the input rectifier filter's electrolytic capacitor to be connected to the network directly through open diodes when the charge current determines its reactance (about 15-30 ohms at a frequency of 50 Hz). 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 LE40R82BX device:
Installed matrix (LCD panel) LTA400WT-L07 0T1.
The matrix control uses the Timing Controller (T-CON) 4046HDCM4LV0.2.
To power the backlight, a converter is used, combined with the power supply, controlled by the LX1691A PWM controller.
The necessary supply voltages for all nodes of the SAMSUNG LE40R82BX TV are generated by the BN44-00165A power module or its analogs using FSDM0365R (Standby), FAN7382, ICE2BS01, ICE1PCS02 (PFC) microcircuits and 13N50CF, FQPF9N50C, 6N80 type power switches.
MainBoard - the main board (motherboard) is a BN41-00839E module, using chips 7568U-LF, M308AOSGP, EM6A9320BI-4MG, NTP-3000, MAX232EC, 24C256BN and others.
The HTM2-6L2 / 235S tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTA400WT-L07
Type: a-Si TFT-LCD, Panel
Diagonal size: 40 inch
Resolution: 1366x768, WXGA
Display Mode: S-PVA, Normally Black, Transmissive
Active Area: 885.168x497.664 mm
Display Colors: 16.7M (8-bit), CIE1931 72%
Frequency: 60Hz
Lamp Type: CCFL