Saturday 21 December 2019

REPAIRING / SERVICING TV SAMSUNG LE15E31S

Technical description and composition of the SAMSUNG LE15E31S TV, panel type and applicable modules. The composition of the modules.
SAMSUNG
Model: LE15E31S
Chassis / Version: AE15EO
Panel: 15 inch 1024x768
Lamp backlight: 4 Lamp CCFL
Inverter (backlight): integrated into PSU BN41-00347A
PWM Inverter: OZ960
MOSFET Inverter: NTMD6N03
Trans Inverter: TMP90199CT
Power Supply (PSU): BN44-00112A VE15U0 - REV: MP3.1
PWM Power: NCP1200P60
MOSFET Power: P6NK60ZFP
MainBoard: BN41-00449C MP1.2 BN91-0033R PC
IC MainBoard: VCT4862, gm2221, TDA7266D, BA7657F, 24C16, TDA7050, MP1410ES, DS1337
Tuner: BN40-00049A
Control: BN59-00437A
Technical Specifications LE15E31S
SAMSUNG LE15E31S
General repair guidelines for TV LCD
Possible malfunctions
- SAMSUNG LE15E31S TV does not turn on, does not respond to the remote control and control panel buttons, indicators do not light up and do not blink.
With such manifestations, a malfunction is most likely to be detected in the BN44-00112A power supply module. In the absence of the necessary supply voltages 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 the event of breakdowns in the secondary circuits of the converter, it can usually fail in short circuit mode, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse or current sensor at the source of the key most often breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM circuits NCP1200P60 are usually checked by replacing with new, or obviously working.
- 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.
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or inverter. If all the electrolytic capacitors of the filter for the power supply of the inverter are working, make sure that the lamps are working, then you need to check the converter keys and the secondary windings of the transformers.
If in diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during operations, and after their completion, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights up constantly or blinks.
Repair or diagnostics of the BN41-00449C 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). Board repair and replacement of VCT4862, gm2221, TDA7266D, BA7657F, 24C16, TDA7050, MP1410ES, DS1337 microcircuits are carried out with the necessary equipment, and the corresponding element base. Faults associated with the application of BGA processor soldering technologies can be localized by the heating method.
Before changing the tuner BN40-00049A, if it is not possible to tune 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
Owners and users of the SAMSUNG LE15E31S TV should remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device.



The appearance of the MainBoard BN41-00449C is shown in the figure below:
BN41-00449C
BN41-00449C can be used in TVs:
SAMSUNG LE15E31S (Panel 15 inches 1024x768), SAMSUNG LW15M23CX (Panel LTM150XH-L06).
The appearance of the power supply
Main features of the SAMSUNG LE15E31S device:
Installed matrix (LCD panel) 15 inches 1024x768.
To power the backlight, a converter is used, combined with a power supply, controlled by the OZ960 PWM controller. A transformer TMP90199CT is installed in the inverter converter. As power elements of the inverter, keys of the NTMD6N03 type are used.
The necessary supply voltages for all nodes of the SAMSUNG LE15E31S TV are generated by the BN44-00112A power module or its analogs using NCP1200P60 microcircuits and P6NK60ZFP power switches.
MainBoard - the main board (motherboard) is a BN41-00449C module, using VCT4862, gm2221, TDA7266D, BA7657F, 24C16, TDA7050, MP1410ES, DS1337 and other chips.
The tuner BN40-00049A provides the reception of television programs and tuning to channels.