Technical description and composition of the SAMSUNG T27D390EX TV, panel type and applicable modules. The composition of the modules.SAMSUNG LED
Model: T27D390EX
Panel: CY-MH270BGLVBV
LED backlight: M3LE-270SM0-R0 (140514) 36Led
LED driver (backlight): integrated into MainBoard
PWM LED driver: SLC5014R
Power Supply (PSU): Adapter 14V 3.215A 45W; BN44-00721A A4514_DSM
MainBoard: BN41-02152B BN94-07032K
IC MainBoard: NTP7414, 25Q40, 24C256, K4B2G1646Q BCKO
Tuner: BN40-00281A DTOS40EIL276A
Control: Remote: BN59-01189A, IR: BN41-02203A UD590 - TD590_IR
Technical Specifications T27D390EX
SAMSUNG T27D390EX
General repair guidelines for TV LCD LED
Possible malfunctions
- SAMSUNG T27D390EX TV does not turn on at all. There is no reaction to the remote control and control buttons from the front panel. Indicator lights do not light or flash.
With such manifestations, a malfunction is most likely to be detected in the Adapter power module.
This TV model is equipped with an external power adapter type Adapter 14V 3.215A 45W; BN44-00721A A4514_DSM, which the owner can purchase on his own, and repairing it may not always be advisable, however, sometimes there is some reason to open it and eliminate simple typical defects typical of IIPs. In the absence of the necessary supply voltage in the secondary circuits of the converters, it is necessary to check the power switches and rectifier diodes for a possible partial or complete breakdown.
In case of breakdowns of the diodes in the secondary circuits, the converter can operate in emergency short circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key 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), in the absence of external damage and a 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 control. Or the image may appear for a second when turned on and immediately disappears.
As a rule, in such cases there is no display backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
To check the LED strips, to open all the transitions of the LEDs, several tens of volts or more are needed, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED transitions in forward bias, sometimes you can detect the presence of a PN junction of the protective zener diode by connecting the probes in the opposite direction. If the zener diode is broken or broken in short-circuit, then the LED is faulty and needs to be replaced.
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the BN41-02152B 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). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the elements NTP7414, 25Q40, 24C256, K4B2G1646Q BCKO. BGA chip malfunctions are usually easy to detect by warming up.
In the absence of tuning to the channels of terrestrial or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltage at the terminals of the tuner BN40-00281A DTOS40EIL276A. 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.
We recommend the owners of the T27D390EX TV for repair only to qualified specialists with the necessary work experience! Attempts to repair it yourself without the appropriate knowledge and skills can lead to irreversible negative consequences!
The appearance of the MainBoard BN41-02152B is shown in the figure below:BN41-02152B
BN41-02152B can be used in TVs:
SAMSUNG T27D390EX (Panel CY-MH270BGLVBV), SAMSUNG T27D390 (Panel CY-MH270BGLV4H).
Main features of the SAMSUNG T27D390EX device:
Installed matrix (LED-panel) CY-MH270BGLVBV.
To power the backlight LEDs, a converter is used, combined with the main board BN41-02152B, controlled by the SLC5014R PWM controller.
To power all internal components of the SAMSUNG T27D390EX TV, an external adapter type 14V 3.215A 45W is used; BN44-00721A A4514_DSM.
MainBoard - the main board (motherboard) is a BN41-02152B module, using NTP7414, 25Q40, 24C256, K4B2G1646Q BCKO chips and others.
The tuner BN40-00281A DTOS40EIL276A provides the reception of television programs and tuning to channels.