Thursday, 16 January 2020

REPAIR / SERVICING TV SAMSUNG UE42F5500AK


Technical description and composition of the SAMSUNG UE42F5500AK TV, panel type and applicable modules. The composition of the modules.
SAMSUNG LED
Model: UE42F5500AK
Chassis / Version: U85A
Panel: HF420BGA-B1 // T420HVF05.0
T-CON: 50T11-C02 T500HVN05.0 5542T28C06
LED driver (backlight): integrated into PSU; 136 / 182V 280mA, 147 / 195V 280mA
PWM LED driver: MAP3312B
MOSFET LED driver: AOD9N40, AOD5N40
Power Supply (PSU): BN44-00645A L42S1_DSM
PWM Power: SEM3110A, SQD2011K (Standby), SEM3050 (PFC)
MOSFET Power: STD14NM50N, STF13NM60 (PFC)
MainBoard: BN41-01958A
IC MainBoard: CPU: SEMS30, SPI FLASH: W25Q40, SDRAM: K4B2G1646E
Tuner: BN40-00262A DNTS403EH105A DVB-T2 / C
Technical Specifications UE42F5500
SAMSUNG UE42F5500AK
General repair guidelines for TV LCD LED
Repair and diagnostics of any electronic device, in particular SAMSUNG UE42F5500AK, it is advisable to start with a careful external examination of internal and external elements. Sometimes, according to visible changes in the components of the device, it is possible to draw some conclusions and determine the direction of further troubleshooting even before the necessary measurements are taken. Ring cracks in the soldering of the leads of the heating elements, swollen electrolytic capacitors, a charred paint layer on the resistors - all this for the repairman can be a significant clue in the assumptions about the causes and consequences of the malfunction.
If the UE42F5500AK does not turn on, does not respond to the remote control and the front panel buttons, does not blink light bulbs and does not show any signs of operability, the power supply module BN44-00645A L42S1_DSM is probably faulty in this case. When diagnosing and repairing the power supply, after replacing the swollen capacitors of the filters of the secondary rectifiers (if any), you must first check the mains fuse. When it is broken, the power elements of transistors and rectifier bridge diodes should be checked for avalanche (thermal) breakdown.
In most cases, key breakdowns in switching power supplies (SMPS) do 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.
In cases where the SAMSUNG UE42F5500AK TV has lost its image, and the sound is there and all other functions are operational, there is a possibility of a malfunction of the LED driver (converter for powering the HF420BGA-B1 T420HVF05.0 panel backlight LEDs). When you turn on the TV, the image may appear briefly and disappear immediately. It must be borne in mind that with such manifestations the LEDs themselves also fail.
To check the health of the LEDs, as well as contact connections in the ruler circuit, it is necessary to disassemble the panel.
It is impossible to check the line of series-connected LEDs without a special current source, and for this purpose it is not safe to use any voltage sources above 12V for them. Then it remains only to open the panel and check each LED separately. Usually, Chinese 9V-powered multimeters light up one LED slightly if you connect the probes in the forward direction, the red probe to the anode, and the black to the cathode.
The motherboard BN41-01958A must be checked if there is no reaction to the remote control and function buttons, the standby indicator blinks or lights up continuously. In such cases, if the converters or power regulators of the microcircuit are working, a software update may be necessary.
Before changing the tuner BN40-00262A DNTS403EH105A, if it is not possible to tune to television channels, make sure that there are supply voltages that need to be measured at the corresponding terminals of the tuner and check the software for correctness.
It should be remembered! Attempts to repair the SAMSUNG UE42F5500AK TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!


SCHEMATIC MANUAL ----------> Samsung Chassis U85A, Models UE32F45****, UE**F53****, UE**F55****, UE**F5700AW

PSU SCHEMATIC --------------> BN44-00645A Power Supply schematic diagram.


 The appearance of the MainBoard BN41-01958A is shown in the figure below:
BN41-01958A
BN41-01958A can be used in TVs:
SAMSUNG UE39F5500 UE39F5500AK (Panel HF390BGM-C1), SAMSUNG UE32F5300AK (Panel HF320BGA-B1), SAMSUNG UE32F6200 UE32F6200AK (Panel CY-HF320BGLV2V), SAMSUNG UE42F5500AK (Panel HF420BGA-B1), SAMSUNG UE32F4500AK (Panel HF32AGH-R1), SAMSUNG UE32F5500AK UE32F5500AW (Panel HF320BGA-B1), SAMSUNG UE40F6400 UE40F6400AK (Panel CY-HF400CSLV2V), SAMSUNG UE42F5300AK (Panel CY-HF420BGAV1V), SAMSUNG UE32F6400AK UE32F6400 (Panel HF320CSA-B1), SAMSUNG UE39F5300AK UE39F5300 (Panel HF390BGM-C1), SAMSUNG UE46F6200AK (Panel CY-HF460BGLV2V), SAMSUNG UE46F6400AK (Panel СY-HF460CSLV2V), SAMSUNG UE46F6540AB (Panel CY-GF460CSLV3V), SAMSUNG UE40F6540AB (Panel CY-GF400CSLV3V), SAMSUNG UE40F6650 UE40F6650AB (Panel CY-GF400CSLV1V), SAMSUNG UE32F6540 (Panel CY-HF320CSLV3V), SAMSUNG UE46F5300 UE46F5300AK (Panel CY-HF460BGLV1V), SAMSUNG UE32F6800 UE32F6800AB (Panel CY-HF320CSLV1V).
PSU Advanced
The BN44-00645A power module is installed in the UE42F5500AK TV 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 SEM3050 PWM controller does not allow the electrolytic capacitor of the input rectifier filter to be connected directly to the network directly through open diodes, when the value of 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 UE42F5500AK device:
Installed matrix (LED panel) HF420BGA-B1 or T420HVF05.0.
The matrix control uses the Timing Controller (T-CON) 50T11-C02.
To power the backlight LEDs, a converter is used, combined with the power supply, controlled by the MAP3312B PWM controller. As power elements of the LED driver, keys of the type AOD9N40, AOD5N40 are used.
The necessary supply voltages for all nodes of the SAMSUNG UE42F5500AK television are generated by the BN44-00645A power supply module or its analogs using SEM3110A, SQD2011K (Standby), SEM3050 (PFC) microcircuits and power switches of the STD14NM50N, STF13NM60 (PFC) type.
MainBoard - the main board (motherboard) is a BN41-01958A module, using CPU chips: SEMS30, SPI FLASH: W25Q40, SDRAM: K4B2G1646E and others.
The tuner BN40-00262A DNTS403EH105A DVB-T2 / C provides the reception of television programs and tuning to channels.