SAMSUNG LED
Model: LT27H390SIX
Chassis / Version: BN41-02620A
Panel: 27A6LF2E
LED driver (backlight): integrated into MainBoard
PWM LED driver: S5014R (SLC5014R)
MOSFET LED driver: AOD2922
Power Supply (PSU): Adapter
MainBoard: BN41-02620A BN94-12200X
IC MainBoard: CPU, eMMC, DRAM, AUDIO, DC / DC, 24C256
Tuner: BN40-00330B
Appearance
SAMSUNG LT27H390SIX
General recommendations for TV LCD LED repair
Possible malfunctions
- SAMSUNG LT27H390SIX TV does not turn on, does not respond to the remote control and control panel buttons, does not light or blink indicators.
With such manifestations, the adapter power supply usually fails.
The TV is supplied with an external adapter type power supply. TV owners can check by replacing them and purchase them on their own in stores, but the ability to open and eliminate typical defects usually does not create difficulties for the master. Its output voltages should be measured, and if they are absent, check the serviceability of the power switches of the converters and rectifier diodes for the probability of a short circuit.
In case of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and with a short circuit in the power elements of the primary circuit, the mains fuse and / or the current sensor in the source of the key usually breaks off.
Breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM), if they do not have visible damage to the case and an outright short circuit between the terminals, are usually checked by replacing.
- There is no image, there is sound, it reacts to the remote control. Or, immediately after switching on for a second, the image may appear and immediately disappear.
In some of these cases, the malfunction is caused by the lack of display backlighting. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the LED bars for a break 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 is required, and ideally a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters tend to light one 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 pierced in the K / Z.
- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.
Repair or diagnostics of the BN41-02620A motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In cases of complex MB (SSB) repairs and with the necessary skills and equipment, it may sometimes be necessary to replace its CPU, eMMC, DRAM, AUDIO, DC / DC, 24C256 and other possible faulty components. Malfunctions associated with the use of BGA soldering technologies are usually easily diagnosed by the warm-up method.
The malfunction of the BN40-00330B tuner is established after checking the software and all supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be monitored with an oscilloscope.
Additional MainBoard RepairOnce again, we remind TV users: do not try to repair yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repairs to professionals with sufficient experience in the field of electronic repair.
The appearance of the MainBoard BN41-02620A is shown in the figure below:
BN41-02620A
Main features of the SAMSUNG LT27H390SIX device:
Installed matrix (LED panel) 27A6LF2E.
To power the backlight LEDs, a converter combined with the BN41-02620A main board is used, controlled by the S5014R PWM controller (SLC5014R). The keys of the AOD2922 type are used as power elements of the LED driver.
An external adapter type is used to power all internal components of the SAMSUNG LT27H390SIX TV.
MainBoard - the main board (motherboard) is a BN41-02620A module, using CPU, eMMC, DRAM, AUDIO, DC / DC, 24C256 and others.
Tuner BN40-00330B provides reception of television programs and tuning to channels.