Technical description and composition of the SAMSUNG LE26C350D1W TV, panel type and applicable modules. The composition of the modules.
SAMSUNG
Model: LE26C350D1W
Chassis / Version: LE26C350D1WXRU
Panel: T260HA01-DB (DD01)
T-CON: V260B3-XC06
Inverter (backlight): B26HD_AHS REV0.2 BN59-01059B
PWM Inverter: LX6523
MOSFET Inverter: 5N50
Power Supply (PSU): BN44-00368B I26HD_AHS
PWM Power: FAN7530 (PFC), ICE3BR0665J
MOSFET Power: STF13NM60N (PFC)
MainBoard: BN41-01349A SX1 DVB_BL EU BN94-02670A
IC MainBoard: Spi Flash: MX25L4005, Eeprom: 24C256
Tuner: DTOS40CVL081A BN40-00173A
Specifications LE26C350
SAMSUNG LE26C350D1W
General repair guidelines for TV LCD
It is advisable to start the repair of the SAMSUNG LE26C350D1W TV with a careful external examination of all its constituent elements, both internal and external. Inspection is also subject to body elements, control buttons, screen, connectors and cords. Specific external damage can sometimes prompt further actions to determine the malfunction of the TV and localization of the defect before the necessary measurements and waveforms are taken. Elements with visible damage, for example, capacitors swelled up after boiling the electrolyte, charred resistors in certain nodes of the circuit, as well as ring cracks in solders will help the master to guess the causes and possible consequences of the malfunction.
If the power module BN44-00368B I26HD_AHS malfunctions, the external manifestations may be different, for example, SAMSUNG LE26C350D1W does not turn on at all and there is no indication of the indicator lights on the front panel. It is advisable to start the troubleshooting of the power supply module by checking the mains fuse. If it is torn, it is necessary to check first of all the power semiconductor elements - rectifier diodes and the power switch of the converter, which are often found in breakdown conditions in such situations.
It should be remembered that in the practice of repair, usually the power keys of N-Fet converters do not fail due to their poor quality and, in such cases, it is necessary to look for the cause that led to a malfunction and provoked a breakdown of the key. Most often, the culprits of the accident are dried electrolytic capacitors or dangling resistors in the primary circuit, or the PWM controller chip itself may be faulty. It is also necessary to check all the semiconductor elements of the stabilization circuit in the primary and secondary circuits.
This power supply module uses the Active Power Factor Correction (PFC) node and PSU troubleshooting can sometimes be somewhat more complicated. In such cases, it is necessary to check the voltage across the filter capacitor of the CP802 rectifier network in the operating mode of about 380 volts, which indirectly indicates the correct operation of the PFC circuit.
The SAMSUNG LE26C350D1W TV has a BN44-00368B power module, which is combined with an inverter - converter for powering the backlight. When repairing by replacing components, this circuitry option does not complicate the search for defects and is popular in the latest TV models from many manufacturers.
If, when you turn on the TV, the image appears and immediately disappears, or is initially absent when turned on, but there are sound and other functions work, there is a high probability of a malfunction of the inverter (power converter for 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 feeding the inverter should be checked.
Diagnostics of the BN44-00368B I26HD_AHS inverter can be difficult due to the operation of the protection, which is organized by the designers to prevent negative consequences or fires in emergency cases, for example, during short circuits or open circuits in the lamp power supply circuit, as well as their possible depressurization. To make the necessary measurements at control points or to take the necessary waveforms, repairmen have to block the protection circuits in order to be able to diagnose.
Turning off the protection for diagnostic purposes, it must be remembered that in this case there is a risk of failure of the power elements of the inverter. Upon completion of the diagnosis, all regular protection circuits should be restored.
If the motherboard BN41-01349A (BN94-02670A) is faulty, first of all it is necessary to check all the linear power regulators of its chips and, if necessary, update the software. Sometimes you can check the health of MB only by replacement.
Remember! Attempts to self-repair by users of the SAMSUNG LE26C350D1W TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
PSU AdvancedThe LE26C350D1W TV is equipped with a BN44-00368B 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.
Main features of the SAMSUNG LE26C350D1W device:
Installed matrix (LCD panel) T260HA01-DB (DD01).
The matrix control uses the Timing Controller (T-CON) V260B3-XC06.
To power the backlight, an inverter B26HD_AHS is used, it is controlled by the PWM controller LX6523. As power elements of the inverter, keys of the 5N50 type are used.
The necessary supply voltages for all nodes of the SAMSUNG LE26C350D1W TV are generated by the BN44-00368B power module or its analogs using FAN7530 (PFC), ICE3BR0665J microcircuits and power switches of the STF13NM60N (PFC) type.
MainBoard - the main board (motherboard) is a BN41-01349A module, using Spi Flash chips: MX25L4005, Eeprom: 24C256 and others.
The tuner DTOS40CVL081A BN40-00173A provides the reception of television programs and tuning to channels.
