Technical description and composition of the SAMSUNG LE26R81BX TV, panel type and applicable modules. The composition of the modules.SAMSUNG
Model: LE26R81BX LE26R81B LE26R81BS
Chassis / Version: GBP26SEU
Panel: T260XW02 V.5
Inverter (backlight): VIT71008.91 REV.1
PWM Inverter: OZ664SN
MOSFET Inverter: AO4614
Trans Inverter: M32P3-PM, MS2P3-STB, M32P3-PT
Power Supply (PSU): BN44-00191A // BN44-00155A
PWM Power: MC33067P, Q0165R, FAN7530 (PFC), MC33167T
MOSFET Power: 2SK3561
MainBoard: BN41-00878A
IC MainBoard: A21SC, A81SC, AT24C256BN, LE26R81BX / BWT, NTP-3000, 9933B, MP1583DN, MT8291E, MT8293AE, M13S12868A-5T, PI3HDMI
Tuner: HTM-6C / 235S BN40-00099A
Control: BN59-00609A
Appearance
SAMSUNG LE26R81BX
General repair guidelines for TV LCD
It is advisable to start the diagnostics of a malfunction of the SAMSUNG LE26R81BX TV, as well as all others, with an external examination of both external and internal elements. Sometimes, for some visible changes, you can determine the further direction of the defect search and localization of the malfunction before the start of taking the oscillograms and making the necessary measurements at the control points. In most cases, the repairman can guess the causes of the defect and possible consequences by the characteristic signs of typical TV defects, for example, ring cracks formed in the soldering of element outputs, swollen rectifier filter capacitors, charred resistors and other circuit elements.
If the TV does not turn on, no indicators on its front panel are lit or blinking. Also, if the TV does not respond to the remote control and buttons, does not make any sounds or any signs of operability when it is turned on, there is a certain probability that the BN44-00191A power supply module is defective and needs repair. Sometimes with similar manifestations, a problem can only occur in the absence of processor power, but this happens much less often. The diagnostics of the power supply should always be started by checking the fuse and, if it is broken, it is first necessary to check the rectifier bridge diodes and the power switch 2SK3561 for the possibility of an avalanche or thermal breakdown.
In most cases, a breakdown of the N-Fet converter key does 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 MC33067P Q0165R FAN7530 MC33167T from the manufacturer.
The power module uses an active Power Factor Correction (PFC) circuit and the search for faulty elements is somewhat more complicated. An indirect sign of the serviceability of this node is the presence of an increased voltage on the filter capacitor of the rectifier network. In operating mode, it should be about 380 volts for a working module.
Sometimes the SAMSUNG LE26R81BX TV does not have an image, but there is sound, or the image appears and immediately disappears. In this case, there is a high probability of a malfunction of the converter of the backlight lamps, or of the lamps themselves, which can be checked by replacement. In such cases, it is necessary to verify the serviceability of all electrolytic capacitors of the filter according to the power supply of the inverter itself, including the power supply unit (power supply unit).
When repairing the VIT71006.91 inverter, it is often necessary to turn off the protection for diagnostics, which, for the purpose of fire safety, turns it off in any emergency situation, for example, during a malfunction or uneven wear of the lamps, which makes it difficult to find a defect.
Turning off the protection for diagnostic purposes, it must be remembered that in this case there is a risk of failure of the power elements of the inverter. Upon completion of the diagnosis, all regular protection circuits should be restored.
If the motherboard BN41-00878A is faulty, first of all it is necessary to check all the linear power regulators of its chips and, in some cases, change or update the software. If you suspect a EEPROM memory failure, it is recommended that you install a new AT24C256BN chip.
Sometimes you can check the health of MB only by replacement. Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the elements A21SC, A81SC, AT24C256BN, LE26R81BX / BWT, NTP-3000, 9933B, MP1583DN, MT8291E, MT8293AE, M13S12868A-5T, PI3HDMI, Tuner HTM-6C / 235S (BN40-99 .
It should be remembered! Attempts to repair the TV SAMSUNG LE26R81BX, 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!
MainBoard BN41-00878A view is shown in the figure below:BN41-00878A
BN41-00878A can be used in TVs:
SAMSUNG LE26R81BX LE26R81B LE26R81BS (Panel T260XW02 V.5), SAMSUNG LE26S81BS (Panel V260B1-L04 Rev. C1), SAMSUNG LE32S81B (Panel T315XW02), SAMSUNG LE32S81B (Panel V315B1-L01381, LT01301, LT01BC, Rev. SAMSUNG LE46S81B (Panel LTA460WT-L15 0T1), SAMSUNG LE46S81B (Panel LTA460WT-L15), SAMSUNG LE23R81W (Panel T230XW01 V.1), SAMSUNG LE26R82B (Panel T260XW02 V.5), SAMSUNG LE231XB01BW1B231BWBB81B23B81B23B81B23B81B23BX1B231
The power module BN44-00191A is made using the Power Factor Correction (PFC) scheme to eliminate multiple AC harmonics introduced by the device into the mains. The PFC assembly is a Step-Up Converter based on a FAN7530 PWM controller that evenly distributes high-frequency impulses of the charging current of the electrolytic capacitor of the rectifier filter of the mains voltage over a period of 50 Hz. The current of its charge in this case will already be determined not by its reactance (usually 10-30 ohms for the network frequency), but by the elements of the converter. As a result, a change in the amplitude of the pulses (envelope) of the consumed current of the converter will repeat the shape and phase of the input sinusoidal voltage. The availability of the increased voltage (about + 380V) in the operating mode on the capacitor of the line filter indicates the serviceability of the PFC node.The appearance of the power supply
Main features of the SAMSUNG LE26R81BX device:
Installed matrix (LCD panel) T260XW02 V.5.
The VIT71008.91 inverter is used to power the backlight lamps, it is controlled by the OZ664SN PWM controller. The transformer M32P3-PM, MS2P3-STB, M32P3-PT is installed in the inverter converter. As power elements of the inverter, keys of the type AO4614 are used.
The necessary supply voltages for all nodes of the SAMSUNG LE26R81BX TV are generated by the power module BN44-00191A, or its analogs using microcircuits MC33067P, Q0165R, FAN7530 (PFC), MC33167T and power switches of the type 2SK3561.
MainBoard - the main board (motherboard) is a BN41-00878A module, using microchips A21SC, A81SC, AT24C256BN, LE26R81BX / BWT, NTP-3000, 9933B, MP1583DN, MT8291E, MT8293AE, M13S12868A-5T, PI3HDMI and others.
The tuner HTM-6C / 235S BN40-00099A provides the reception of television programs and tuning to channels.
Information from an alternative source:
SAMSUNG LE26R81BX chassis GBP26SEN / SAMSUNG LE26S81B
Panel Type (Matrix): T260XW02 V.5
Motherboard: BN41-00878A, CPU -, Memory - A21SC, A81SC, AT24C256BN, Flash - (sticker LE26R81BX / BWT 1020 (801A)), Sound - NTP-3000, Tuner - HTM-6C / 235S BN40-00099A, Other ICs 9933B, MP1583DN, MT8291E, MT8293AE, M13S12868A-5T, PI3HDMI 1212BE, RT9173B, SDP64, WT61P6S 727 Power Board STB, M32P3-PT T-CON - T315XW02 VC / V9 T260XW02 VA 06A94-1A
Remote control: BN59-00609A Inverter Board - VIT71008.91
Invertor: T51.0034.211 E2, Other ICs - 4614, ADA04 ADABACT 0721R, LM339A, LM358A, OZ964SN Schema TV Samsung LE23R81BX, LE26R81BX, LE26R82BX chassis GBP23SEN / SEU, GBP26SEN / SEU
Additional technical information about the panel:
Brand: AUO
Model: T260XW02 V5
Type: a-Si TFT-LCD, Panel
Diagonal size: 26.0 inch
Resolution: 1366x768, WXGA
Display Mode: VA, Normally Black, Transmissive
Active Area: 575.769x323.712 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 800: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 15/5 (Tr / Td); 8 (G to G)
Frequency: 60Hz
Lamp Type: 8 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V