Tuesday 7 January 2020

REPAIR / SERVICING TV SAMSUNG UE37D5520RW

Technical description and composition of the SAMSUNG UE37D5520RW TV, panel type and applicable modules. The composition of the modules.
SAMSUNG LED
Model: UE37D5520RW UE37D5520
Chassis / Version: U66A / CN01
Panel: LD370BGB-C1
T-CON: T315HW04 VB CTRL BD
LED driver (backlight): integrated into PSU
PWM LED driver: SLC3011M
MOSFET LED driver: FDT3N40
Power Supply (PSU): BN44-00422B PD46A0_BDY
PWM Power: 3BR1765JZ (Standby), 1HS01G (PWM resonant), FA5591N (PFC)
MOSFET Power: K8A50D, 5N50
MainBoard: BN41-01660B
IC MainBoard: SEMS21 1108A-LF, K9GAG08U0E
Tuner: BN40-00196A DTOS40FVH082A
Technical Specifications UE37D5520
SAMSUNG UE37D5520RW
General repair guidelines for TV LCD LED
Possible malfunctions
- The SAMSUNG UE37D5520RW TV does not turn on, does not respond to the remote control and the control panel buttons, does not light up or blink indicators.
Sometimes, with similar manifestations, the defect is caused by faulty elements in the main power module BN44-00422B. It is necessary to measure its output voltages and, in case of their complete or partial absence, check the serviceability of power switches (K8A50D, 5N50) and rectifier diodes for a possible breakdown. The converter on the 3BR1765JZ PWM controller (Standby) must be checked first.
It should be borne in mind that in practice, during breakdowns in the secondary circuits of the converters, they can usually fail in short circuit mode, and during short circuit in the power elements of the primary circuit, the main fuse or current sensor at the source of the key most often 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) 3BR1765JZ (Standby), 1HS01G (PWM resonant), FA5591N (PFC), in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
The operability of the PFC node can be indirectly judged by the presence of an increased voltage (380-400V) on the filter capacitor of the rectifier network in operating mode.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
Often in such cases, there is no LED backlight. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
To detect a break in the LED lines without disassembling the panel, a current source is required. It is impossible to open transitions connected in series with a simple multimeter; voltage of several tens of volts is necessary.
- The indicator blinks or glows constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the BN41-01660B 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). In cases of attempts to repair the MB board (SSB), it is necessary to check the serviceability of its elements - SEMS21 1108A-LF, K9GAG08U0E which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its conclusions with the board (it is diagnosed by heating).
Malfunction of the tuner BN40-00196A DTOS40FVH082A 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 controlled by an oscilloscope.
It should be remembered! Attempts to self-repair a SAMSUNG UE37D5520RW 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!

SCHEMATICS --------------> Samsung UE37D5520RW 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.


The appearance of the MainBoard BN41-01660B is shown in the figure below:
BN41-01660B
BN41-01660B can be used in TVs:
SAMSUNG UE40D5500 UE40D550K1W UE40D5500RW (Panel LD400BGB-A2), SAMSUNG UE37D5520RW UE37D5520 (Panel LD370BGB-C1), SAMSUNG UE37D5500 RW (Panel LD370BGB-C1).
The appearance of the power supply
Main features of the SAMSUNG UE37D5520RW device:
Installed matrix (LED panel) LD370BGB-C1.
The matrix control uses the Timing Controller (T-CON) T315HW04.
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 UE37D5520RW TV are generated by the BN44-00422B power supply module or its analogs using 3BR1765JZ (Standby), 1HS01G (PWM resonant), FA5591N (PFC) microcircuits, and K8A50D, 5N50 type power switches.
MainBoard - the main board (motherboard) is a BN41-01660B module, using microchips SEMS21 1108A-LF, K9GAG08U0E and others.
The tuner BN40-00196A DTOS40FVH082A provides the reception of television programs and tuning to channels.