Technical description and composition of the SONY KDL-37EX402 TV, panel type and applicable modules. The composition of the modules.SONY
Model: KDL-37EX402
Chassis / Version: AZ1N_3a-2
Panel: T370HW03 V.8 181107411
T-CON: T315HW04 V0 5537T05C23 185774111
Inverter (backlight): 4H.V2988.041 V298-5XX 1937T05007 // 185770111 E206453
Power Supply (PSU): APS-253 G2ME 147420121
PWM Power: CXA3809M, MIP2H2 (Standby)
MainBoard: 1-881-019-13 BEN A-1763-564-A A1763564A
IC MainBoard: PNX85433EH1, K4T5116306-HCE7, H27U1G8F2BTR, TDA19997HL / C1
Tuner: ENGS7401D5F
Control: IR: 1-881-589-11 (173162311), RM-ED022
Technical Specifications KDL-37EX402
SONY KDL-37EX402
General recommendations for repairing TV LCD
It is advisable to start the repair and diagnostics of the SONY KDL-37EX402 TV with a careful external examination of the internal and external elements, including case parts, a display, buttons and cables. Often, by the external signs and nature of some damage, it is possible to draw preliminary conclusions and determine a further algorithm for troubleshooting. 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 leads, swollen rectifier filter capacitors, charred resistors and other circuit elements.
In cases when the SONY KDL-37EX402 TV does not turn on, does not respond to the remote control and buttons, no indicators on the front panel light up or blink, and there are no sounds and no signs of operability when turning on, the APS-253 power supply module is most likely faulty G2ME 147420121 or, which is much less common, there is no processor power on the motherboard. In this case, first of all, it is necessary to check the fuse at the mains input. If it is broken, then you should check for breakdown of the PN junctions of the rectifier bridge diodes and the key transistor of the N-FET converter, which can either be on a separate radiator or integrated with a PWM controller in a common chip. Possible options.
It should be remembered that in the practice of repair, usually the power keys of N-Fet converters do not fail due to their poor quality and, in such cases, it is necessary to look for the cause that led to a malfunction and provoked a breakdown of the key. Most often, the culprits of the accident are dried electrolytic capacitors or dangling resistors in the primary circuit, or the MIP2H2 PWM controller chip itself may be faulty (7). It is also necessary to check all the semiconductor elements of the stabilization circuit in the primary and secondary circuits.
When using a power factor correction unit (PFC) in the power modules, troubleshooting becomes somewhat more complicated and requires additional experience and knowledge of their operation.
If the SONY KDL-37EX402 does not have an image, but there is sound, there is a possibility of a malfunction of the backlight or power converter. You should also make sure that the electrolytic capacitors of the secondary rectifiers of the common power supply are working.
Diagnosis and repair of the inverter is often complicated by the organization of special protection circuits, which is necessary for fire safety and turns off the inverter in any emergency situation, for example, when the lamps are worn or depressurized. Often, to localize a defect, its blocking is required.
It should be remembered that in such cases there is a risk of failure of the power elements of the inverter and to take special care. After carrying out repairs, the protection circuit must be restored for further safe operation of the TV.
If the BEN A1763564A motherboard is faulty, first of all it is necessary to check all the linear power regulators of its chips and, if necessary, update the software. Sometimes you can check the health of MB only by replacement.
Before changing the ENGS7401D5F tuner, if it is not possible to tune to television channels, make sure that there are supply voltages, including varicap power (30-33V), which must be measured on the corresponding tuner pins.
It should be remembered! Attempts to repair the SONY KDL-37EX402 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!
Service manual / schematic diagram -------------------> Sony KDL-32EX401, 32EX402, 37EX402, 40EX402, 46EX402 chassis AZ1-N(3a-2)
psu / schematic diagram -------------------> APS-252, APS-253, APS-254 Power supply
The appearance of MainBoard 1-881-019-13 is shown in the figure below:1-881-019-13
1-881-019-13 can be used in TVs:
SONY KDL-32EX401 (Panel LTY320HM03), SONY KDL-32EX600 (Panel V315H3-LE1), SONY KDL-37EX402 (Panel T370HW03 V.8 181107411).
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the APS-253 module provides for the use of a Power Factor Correction unit. The PFC circuit is a flyback converter based on the FA5501A PWM controller. The reactance of an electrolytic capacitor of a line filter at a frequency of 50-60 Hz is usually not more than 20-30 ohms and its charge directly from the network through open diodes could reach tens of amperes per pulse if no filtering were applied.
As a result of the PFC conversion, an increased voltage on the capacitor (about 380V) cannot directly open the rectifier diodes, on the anode of which the voltage will always be slightly less (about 300V) and then its charging current will always be limited by the elements of the PWM controller. As a result, the envelope of the high-frequency pulses of the consumed current will repeat the shape and phase of the input sinusoidal voltage. The presence of an increased voltage (+ 380V) on the network capacitor indicates the serviceability of the PFC node.
The appearance of the power supply
Main features of the device SONY KDL-37EX402:
Installed matrix (LCD panel) T370HW03 V.8 181107411.
The matrix control uses the Timing Controller (T-CON) T315HW04.
To power the backlight, an inverter 4H.V2988.041 is used.
The formation of the necessary supply voltages for all nodes of the SONY KDL-37EX402 TV is carried out by the APS-253 power module, or its analogs using CXA3809M, MIP2H2 (Standby) microcircuits.
MainBoard - the main board (motherboard) is a module 1-881-019-13, using chips PNX85433EH1, K4T5116306-HCE7, H27U1G8F2BTR, TDA19997HL / C1 and others.
The ENGS7401D5F tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: T370HW03 V8
Type: a-Si TFT-LCD, Panel
Diagonal size: 37 inch
Resolution: 1920x1080, FHD
Display Mode: AMVA, Normally Black, Transmissive
Active Area: 819.36x460.89 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Brightness: 450 cd / m²
Contrast Ratio: 5000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 6.5 (G to G)
Frequency: 60Hz
Lamp Type: 10 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V
