Wednesday 8 January 2020

REPAIR / SERVICING TV SAMSUNG UE40D5520RW

Technical description and composition of the SAMSUNG UE40D5520RW TV, panel type and applicable modules. The composition of the modules.
SAMSUNG LED
Model: UE40D5520RW
Chassis / Version: U66A / CN01
Panel: LD400BGC-C1 DD01
LED driver (backlight): integrated into PSU
PWM LED driver: SLC3011M
MOSFET LED driver: FDT3N40
Power Supply (PSU): BN44-00422B PD46AD_BDY
PWM Power: 3BR1765JZ (Standby), 1HS01G (PWM resonant), FA5591N (PFC)
MainBoard: BN41-01660A
IC MainBoard: SEMS21 1108A-LF, NAND: K9GAG08U0E, DDR: D9LGQ, EEPROM: ATMLH108 2ECL
Tuner: DTM-8BW125S BN40-00221A
Technical Specifications UE40D5520
SAMSUNG UE40D5520RW
General repair guidelines for TV LCD LED
Diagnostics of malfunctions and repairs SAMSUNG UE40D5520RW, as well as other electronic devices, it is recommended to start with an external examination of the external and internal elements. From the visible changes in the state of components, it is usually possible to determine the further direction of troubleshooting and localization of the defect before the necessary measurements are taken. Electrolytic capacitors of filters with a swollen body, as well as ring cracks or a layer of coal on burned-out resistors formed in soldered terminals of heating elements, sometimes tell the repairman the causes of the malfunction and possible consequences.
Sometimes the SAMSUNG UE40D5520RW TV simply does not turn on. No control lights on the front panel are lit or blinking, the TV does not respond to the remote control and does not make any sounds or any signs of life when turned on. The most likely cause of the malfunction is a failure of the PD46A0 BDY BN44-00422B common power supply module. If it is working properly, you need to check the processor batteries on the SSB (Main Board). It is advisable to start the troubleshooting of the power supply module by checking the state of the electrolytic capacitors of the rectifier filters and the mains fuse. Defective capacitors should be replaced. If the mains fuse is broken, it is necessary to check first of all the power semiconductor elements - rectifier diodes and transistors, which are often found in such a state of breakdown.
As a rule, the keys in switching power supplies (SMPS) are reliable enough and rarely fail for no reason to be looked for by checking other components of the circuit - electrolytic capacitors, resistors and semiconductor elements of the primary circuit. The PWM chip is checked by replacing it with a known good one.
If there is no image when you turn on the SAMSUNG UE40D5520RW, or it appears for a second and disappears, but there is sound, most likely there is a malfunction in the backlight LED circuit of the LD400BGC-C1 DD01 panel, or in their power converter. It is necessary to check the electrolytic capacitors of the filter of the secondary rectifiers in the general power supply unit.
A malfunction in the backlight circuits often occurs due to a break in the power supply lines of the LED lines. It requires disassembling the panel and checking the LEDs themselves, the soldering of their terminals, as well as the reliability of the connections in the connectors and the soldering of the terminals.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes.
In cases of attempts to repair the BN41-01660A motherboard, it is necessary to check the operability of the stabilizers or power converters of its microcircuits and, if possible, update the software (software). BGA chips can in most cases be diagnosed by local heating.
If you suspect a malfunction of the DTM-8BW125S BN40-00221A tuner, first of all, you need to make sure that the voltage of the varicaps (30-33V) is on the corresponding output of the tuner, as well as other voltage supplying it.
Once again, remind users! Attempts to self-repair a SAMSUNG UE40D5520RW TV without the appropriate qualifications and experience can lead to its complete non-repairability!


SCHEMATIC MANUAL ---------------> Samsung UE40D5520 Chassis U66A.

Chassis : U66A Model : UE32D55**R*, UE37D55**R*, UE40D55**R*, UE46D55**R*, UE32D57**RS, UE37D57**RS, UE40D57**RS, UE46D57**RS
Chassis : U57A Model : UE32D50**PW, UE37D50**PW, UE40D50**PW, UE46D50**PW, UE32D40**NW
Chassis : U57B Model : UE19D40**NW, UE22D50**NW, UE27D50**NW

PSU SCHEMATIC ----------------->  BN44-00422B Power SUPPLY

The appearance of the MainBoard BN41-01660A is shown in the figure below:
BN41-01660A
BN41-01660A can be used in TVs:
SAMSUNG UE40D5520RW (Panel LD400BGC-C1 DD01), SAMSUNG UE32D5500 RW (Panel LD320BGC-C1), SAMSUNG UE32D5520RW UE32D5520 (Panel LD320BGC-C1).
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the BN44-00422B module provides for the use of a Power Factor Correction unit. The PFC circuit is a flyback converter based on the 1HS01G PWM controller. The reactance of an electrolytic capacitor of a line filter at a frequency of 50-60 Hz is usually not more than 20-30 ohms and its charge directly from the network through open diodes could reach tens of amperes per pulse if no filtering were applied.
As a result of the PFC conversion, an increased voltage on the capacitor (about 380V) cannot directly open the rectifier diodes, on the anode of which the voltage will always be slightly less (about 300V) and then its charging current will always be limited by the elements of the PWM controller. As a result, the envelope of the high-frequency pulses of the consumed current will repeat the shape and phase of the input sinusoidal voltage. The presence of an increased voltage (+ 380V) on the mains capacitor indicates the serviceability of the PFC node.
The appearance of the power supply
Main features of the SAMSUNG UE40D5520RW device:
Installed matrix (LED panel) LD400BGC-C1 DD01.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by the SLC3011M PWM controller. As power elements of the LED driver, keys of the FDT3N40 type are used.
The necessary supply voltages for all nodes of the SAMSUNG UE40D5520RW TV are generated by the BN44-00422B power module, or its analogs using 3BR1765JZ (Standby), 1HS01G (PWM resonant), FA5591N (PFC) microcircuits.
MainBoard - the main board (motherboard) is a BN41-01660A module, using microchips SEMS21 1108A-LF, NAND: K9GAG08U0E, DDR: D9LGQ, EEPROM: ATMLH108 2ECL and others.
The DTM-8BW125S BN40-00221A tuner provides TV reception and channel tuning.