Technical description and composition of the SAMSUNG UE55NU7470U TV, panel type and applicable modules. The composition of the modules.SAMSUNG LED
Model: UE55NU7470U
Chassis / Version: FA01
Panel: CY-NN055HGLV5H
LED driver (backlight): integrated into PSU
Power Supply (PSU): BN44-00932C REV1.2 L55E6_NHS
PWM Power: PFC, PWM
MOSFET Power: N-FET TO-220
MainBoard: BN41-02635B BN94-13299E
IC MainBoard: CPU, eMMC, DRAM, AUDIO: TAS5749M
Tuner: BN40-00331A
Control: WIFI: WDN220M BN59-01299A
Technical Specifications UE55NU7470U
SAMSUNG UE55NU7470U
General repair guidelines for TV LCD LED
Possible malfunctions
- SAMSUNG UE55NU7470U does not turn on, does not respond to buttons and remote control, indicators on the front panel do not light up and do not blink.
In such cases, the fault should be sought first in the BN44-00932C power supply module. It is then necessary to measure its output voltages and, if they are absent, you should check the power switches (N-FET TO-220) and the rectifier diodes of the converters for a short circuit probability.
In case of breakdowns of semiconductors in the secondary circuits, the converter can usually work abnormally in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse often breaks.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode, or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damping circuits, or negative feedback elements in the stabilization circuit. PFC, PWM PWM controllers, in the absence of visible damage or explicit short-circuit between the terminals, are checked by replacing with new ones, or obviously working.
- There is no image, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn on and immediately disappears.
Usually in such cases, a malfunction is detected in the backlight nodes of the LED panel. The reason may be a break in the LEDs, in the stabilization of their power supply, or in the violation of the contact connections of the strings
When diagnosing, it is necessary to take into account that it is impossible to check the open in the chain of LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally, a current source. By opening the panel, each LED can be checked separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect probes in the forward direction to it. In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the BN41-02635B motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Testing or replacing elements of CPU, eMMC, DRAM, AUDIO requires the necessary training and professional skills in repairing modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by warming up.
Before changing the tuner BN40-00331A, if there is no possibility of tuning to television channels, you should make sure that there are supply voltages that must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Attention to users! Self-repair of a SAMSUNG UE55NU7470U TV without the appropriate qualifications and necessary experience can lead to its complete non-repairability!
The appearance of the MainBoard BN41-02635B is shown in the figure below:BN41-02635B
The appearance of the power supply
Main features of the SAMSUNG UE55NU7470U device:
Installed matrix (LED-panel) CY-NN055HGLV5H.
To power the backlight LEDs, a converter is used, combined with a power supply.
The necessary supply voltages for all nodes of the SAMSUNG UE55NU7470U television are generated by the BN44-00932C power supply module or its analogs using PFC, PWM microcircuits, and N-FET TO-220 type power switches.
MainBoard - the main board (motherboard) is a BN41-02635B module, using CPU, eMMC, DRAM, AUDIO: TAS5749M and others.
The tuner BN40-00331A provides the reception of television programs and tuning to channels.
