Technical description and composition of the SAMSUNG LE37R81B TV, type of panel and applicable modules. The composition of the modules.SAMSUNG
Model: LE37R81B
Chassis / Version: BP37EO
Panel: T370XW02 V.5
T-CON: T370XW02 V5 AUO, BD8156EFV, RSS065 (8), ON324, AS15-F, W9864G2GH-7, AUO-039
Inverter (backlight): 4H.V1448.481 C1
PWM Inverter: ST324, OZ9643SN.
MOSFET Inverter: P2804ND5G (5).
Trans Inverter: 6025B73VA17 GP-03
Power Supply (PSU): BN44-00157A
PWM Power: TDA4863-2 (PFC), VIPer22A (Standby), F9222L (PWM resonant)
MainBoard: BN41-00839B, BN94-0325E.
Tuner: TCLW3001PD32S BN40-00078A
Technical specifications LE37R81B
SAMSUNG LE37R81B
General repair guidelines for TV LCD
Repair of a SAMSUNG LE37R81B TV is advisable to start with a careful external examination of all its constituent elements, both internal and external. Inspection is also subject to body elements, control buttons, screen, connectors and cords. Visible damage to elements can sometimes suggest directions for finding a defect even before the necessary measurements are taken. Carbonized paint on the upper layer of resistors, electrolytic capacitors of rectifier filters deformed after boiling, cracked soldering at the terminals of the elements can often tell the cause of the defect and possible consequences.
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 turned on, there is a certain chance that the BN44-00157A 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. It is advisable to start the troubleshooting of the power supply module by checking the mains fuse. If it is torn, it is necessary to check first of all the power semiconductor elements - rectifier diodes and the power switch of the converter, which are often found in breakdown conditions in such situations.
It should be borne in mind that in the practice of repair it is extremely rare that key transistors of the N-FET type fail for no reason that should be sought by checking other components, for example, a breakdown of the key can provoke faulty elements of the damper circuits, either dried electrolytic capacitors or dangling resistors of the primary circuit of the PSU, involved in the stabilization process. In this case, all semiconductor elements of the strapping of the VIPer22A PWM controller microcircuit are subject to verification, which it is desirable to verify by replacement.
It is somewhat more difficult to look for a malfunction in the converter of the power module with an active KKM (power factor corrector).
In cases where the SAMSUNG LE37R81B TV has lost an image, and the sound is there and all other functions are operational, there is a possibility of a malfunction of the inverter (converter for powering the backlight). 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.
Diagnostics of the 4H.V1448.481 C1 inverter can be difficult due to the operation of the protection, which is organized by the designers to prevent negative consequences or fires in emergency cases, for example, during short circuits or breaks in the lamp power supply circuit, as well as their possible depressurization. To make the necessary measurements at control points or to take the necessary waveforms, repairmen have to block the protection circuits in order to be able to diagnose.
It should be remembered that when the protection is turned off, there is always a risk of failure of the power elements of the inverter during diagnosis. After repair, it is imperative to restore all standard converter protection circuits.
Diagnostics and repair of the motherboard BN41-00839B (BN94-0325E). performed by checking the performance of power stabilizers or by updating software (software).
Owners and users of the SAMSUNG LE37R81B TV must 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!
One of the typical defects of a SAMSUNG LE37R81B TV can occur in the T370XW02 V.5 panel.
External manifestations: color distortion in the image as a negative in the image, light tones predominate. Usually in such cases, the AS15-F gamma corrector is faulty. Another indicator of its malfunction is an excessively strong heating, which in practice allows you to do without measuring the voltage gradations of gray.
In most cases, replacing the AS15-F solves the problem.
It should be remembered that similar symptoms can cause faults in the column drivers of the panel, which is usually indicated by interference in the form of even vertical stripes on the screen. Then, after replacing the AS15-F, the situation does not change. Drivers are in loops and cannot be replaced. In this case, it is necessary to replace the glass panel.
PSU SCHEMATICS ------> BN44-00157A.
The appearance of the MainBoard BN41-00839B is shown in the figure below:BN41-00839B
BN41-00839B can be used in TVs:
SAMSUNG LE37R81B (Panel T370XW02 V.5), SAMSUNG LE40R81 (Panel LTA400WT-L06 (L09)).
PSU Advanced
The LE37R81B model uses a BN44-00157A power supply unit using the PFC (Power Factor Correction) node - an active filter of the highest harmonics of the current consumption. In fact, it is a boost converter based on the TDA4863-2 PWM controller, which eliminates the charge current of the electrolytic capacitor of the rectifier filter directly from the network through open diodes, when its charging current is determined by its reactance.
As a result of the operation of the converter, the envelope of the high-frequency pulses of the input current of the converter will repeat the shape and phase of the input voltage. The health of the PFC node can be indirectly judged by the presence of an increased DC voltage (about + 380V) on the capacitor of the rectifier network in operating mode.
The appearance of the power supply
Main features of the SAMSUNG LE37R81B device:
Installed matrix (LCD panel) T370XW02 V.5.
The matrix control uses the Timing Controller (T-CON) T370XW02.
To power the backlight, an inverter 4H.V1448.481 is used, it is controlled by a PWM controller ST324, OZ9643SN .. A transformer 6025B73VA17 GP-03 is installed in the inverter converter. As power elements of the inverter, keys of the type P2804ND5G (5) are used.
The necessary supply voltages for all nodes of the SAMSUNG LE37R81B 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 BN41-00839B module.
The tuner TCLW3001PD32S BN40-00078A provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: AUO
Model: T370XW02 V5
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: 500 cd / m²
Contrast Ratio: 1500: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
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