Technical description and composition of the SAMSUNG LE37S81B TV, panel type and applicable modules. The composition of the modules.SAMSUNG
Model: LE37S81B
Panel: T370XW02 V.6
Inverter (backlight): 4H.V144B.481 C1 DARFON
PWM Inverter: OZ9645N (20), 358, 324
Trans Inverter: 6026B75JF05 OZ9645N (20), 358, 324
Power Supply (PSU): BN44-00157A
PWM Power: TDA4863-2 (PFC), VIPer22A (Standby), F9222L (PWM resonant)
MainBoard: BN94-01352R
IC MainBoard: MT8293AE, AP358, NTP-3000
Tuner: BN40-00099A HTM-6C 235S
Technical Specifications LE37S81B
SAMSUNG LE37S81B
General repair guidelines for TV LCD
SAMSUNG LE37S81B TV, like any others, it is advisable to start repairing with an inspection of internal and external elements. Visible damage to elements can sometimes suggest directions for finding a defect even before the necessary measurements are taken. Ring cracks in the soldering of the leads of the elements, deformed electrolytic capacitors, charred resistors - all this for the repairman can be a hint in assumptions about the causes and consequences of the malfunction.
Faults in the BN-00157A power supply module can be expressed in different ways, for example, SAMSUNG LE37S81B does not turn on at all and the control lamps on its front panel do not light up and do not blink, and there are no signs of operability. When diagnosing and repairing the power supply, first of all, it is necessary to check the fuse and, if it is broken, it is necessary to identify the cause. Often in such cases, an avalanche (thermal) breakdown is detected in the power semiconductor elements of the module - rectifier diodes or power key.
Power switches in flyback converters fail extremely rarely for no reason and, when they are broken, it is necessary to look for a malfunction in the stabilization circuits by checking electrolytic capacitors, semiconductor devices, and resistors in the primary circuit. The reason may be a malfunction of the PWM controller chip, which can only be checked by replacing it with a new or obviously working one.
If the power module uses an active KKM circuit (power factor control), troubleshooting is somewhat more complicated.
In cases where the SAMSUNG LE37S81B TV has lost an image, and the sound is there and all other functions are operational, there is a possibility of an inverter (converter for powering the backlight) malfunction. When you turn on the TV, the image may appear briefly and immediately disappear. It must be borne in mind that with such manifestations, the lamps themselves also fail, the malfunction of which can be detected by replacement, by connecting to the connectors for diagnostics that are known to be serviceable and suitable in power.
Repair of the 4H.V144B.481 C1 DARFON inverter can often be somewhat complicated by the use of special protection circuits, which are designed to disconnect it in emergency cases for fire safety when the lamps are depressurized, or short circuits or breaks in high-voltage circuits and connections. Sometimes it becomes necessary for diagnostic purposes to block the protection circuits in order to be able to make the necessary measurements at the control points of the circuit.
In such cases, special care should be taken during diagnosis, and after completion of all repair work, it is necessary to restore the circuit and the inverter protection for further safe operation of the TV.
When trying to repair the motherboard, you should first check the serviceability of linear stabilizers or power converters of microcircuits and, if necessary, update the software (software). Often, the MB (SSB) card must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - MT8293AE, AP358, NTP-3000 and replace failed chips with new ones.
It should be remembered! Attempts to repair the TV SAMSUNG LE37S81B, 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 Chassis GJA26SEU-GJA46SEU.
FOR MODELS ----> Samsung LE26S81BX, LE26S86BD, LE32S81BX, LE32S86BD, LE37S81BX, LE40S81BX, LE40S86BD, LE46S81BX
SCHEMATICS ------> Samsung Chassis GJA26TSA-GJA46TSA.
FOR MODELS Samsung LE26S81BHX, LE32S81BHX, LE37S81BHX, LE40S81BHX, LE46S81BHX
PSU SCHEMATIC -----> BN44-00157A.
The power module BN44-00157A is made using the Power Factor Correction (PFC) scheme to eliminate multiple AC harmonics introduced into the power supply by the device. The PFC node is a Step-Up Converter based on a TDA4863-2 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 LE37S81B device:
Installed matrix (LCD-panel) T370XW02 V.6.
To power the backlight, an inverter 4H.V144B.481 is used, it is controlled by the PWM controller OZ9645N (20), 358, 324. A transformer 6026B75JF05 OZ9645N (20), 358, 324 is installed in the inverter converter.
The necessary supply voltages for all nodes of the SAMSUNG LE37S81B TV are generated by the BN44-00157A power module or its analogs using TDA4863-2 (PFC), VIPer22A (Standby), F9222L (PWM resonant) microcircuits.
MainBoard - the main board (motherboard) is a module BN94-01352R, using chips MT8293AE, AP358, NTP-3000 and others.
Tuner BN40-00099A HTM-6C 235S provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: AUO
Model: T370XW02 V6
Type: a-Si TFT-LCD, Panel
Diagonal size: 37 inch
Resolution: 1366x768, WXGA
Display Mode: AMVA, Normally Black, Transmissive
Active Area: 819.6x460.8 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 550 cd / m²
Contrast Ratio: 1500: 1
Display Colors: 16.7M (8-bit)
Response Time: 15/5 (Tr / Td); 8 (G to G)
Frequency: 60Hz
Lamp Type: CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V