Technical description and composition of the TV SHARP LC-42AD5RU-GY, type of panel and applicable modules. The composition of the modules.SHARP
Model: LC-42AD5RU-GY
Chassis / Version: kd890
Panel: LK420T3LZ10X
T-CON: CPWBX3796TPZ
Power Supply (PSU): DPS-267BP RDENCA227WJQZ
PWM Power: L6562 (PFC), DAS01A, DLA001 (PWM Push-pull), DAP011 (PWM Flyback)
MainBoard: KD890 XD890WJN5 + DUNTKD984WE + D604WJ
IC MainBoard: TDA8931T
Tuner: XD890WJN QPWBND984WJN1
Technical Specifications LC-42AD5RU
SHARP LC-42AD5RU-GY
General recommendations for repairing TV LCD
Like any other TV, it is advisable to start repairing the SHARP LC-42AD5RU-GY with an external examination of the visible changes in the external and internal elements. Sometimes, only by some signs can we determine the further direction of the localization of the malfunction. Electrolytic capacitors of filters with a swollen casing, as well as ring cracks formed in the soldered leads of heating elements, or a layer of coal on burnt resistors sometimes tell the repairman the causes of the malfunction and possible consequences.
If the power supply module DPS-267BP A fails, the external manifestations may be different, for example, the SHARP LC-42AD5RU-GY does not turn on at all and there is no indication of the indicator lights on the front panel. In this case, the diagnosis and repair of the common power supply should always be started by checking the mains fuse. When it breaks, it is advisable to check for a breakdown, first of all, all power semiconductor elements of the converter and the rectifier diode bridge of the network, as well as the large electrolytic capacitor of the filter of the network rectifier and the key transistor.
It should be remembered that the N-FET keys used in flyback converters rarely fail for no reason that must be sought by checking other elements of the circuit. Often the breakdown is caused by malfunctions of electrolytic capacitors or semiconductor elements in the primary circuit, or by a break in the resistors in the stabilization circuits. The PWM controller chip can also cause a breakdown of the power switch of the converter.
If the power module uses an active KKM circuit (power factor control), troubleshooting is somewhat more complicated.
If the SHARP LC-42AD5RU-GY does not have an image, there is sound and the channels are switched, there is a possibility of a malfunction of the display backlight, or their power converter - inverter. Sometimes when you turn on the image appears and disappears immediately. In such cases, it is necessary to check the electrolytic capacitors of the power filter of the inverter itself, including in the secondary rectifier of the main PSU.
The operation of the power circuits of the inverter and the backlight in the normal mode are controlled by special protection, which is organized for fire safety, for example, to disconnect during short circuits or breaks in high-voltage connections or when the lamps are depressurized. This protection makes it difficult to diagnose and repair the inverter.
When diagnosing with the protection off, special precautions must be taken, because there is a risk of failure of the power elements of the inverter. After the diagnosis, it is imperative to restore the protection circuits for the inverter to operate normally.
The DUNTKD984WE D604WJ motherboard must be checked if there is no reaction to the remote control and function buttons, the standby indicator blinks or lights up continuously. In such cases, if the power supply circuits of the microcircuits are working, a software update may be necessary. In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its TDA8931T chips and other possible faulty components.
If the TV works normally from external devices, but does not tune into television channels, the tuner XD890WJN may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals, as well as the power supply of varicaps (30-33V).
Attention to the owners! Attempts at self-repair of the SHARP LC-42AD5RU-GY TV are not recommended by the manufacturer and can lead to serious negative consequences!
Service manual / schematic diagram -------------------> SHARP LC-42AD5RU Sharp LC-42AD5E, LC-42AD5E, LC-42AD5RU, LC-42AD5S
1. Service Manual with Schematic Diagram 144 страниц 2008 г. на модели LC-42AD5E, LC-42AD5RU, LC-42AD5S - 17MB62 CHASSIS.
2. Service Manual with Schematic Diagram 31 pages 2007 on the model LC-42AD5E, LC-42AD5RU, LC-42AD5S.
The appearance of the MainBoard KD890 is shown in the figure below:Kd890
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the DPS-267BP module provides for the use of a Power Factor Correction unit. The PFC circuit is a flyback converter based on the L6562 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 SHARP LC-42AD5RU-GY device:
Installed matrix (LCD panel) LK420T3LZ10X.
The matrix control uses the Timing Controller (T-CON) CPWBX3796TPZ.
The necessary supply voltages for all nodes of the SHARP LC-42AD5RU-GY TV are generated by the DPS-267BP power supply module or its analogs using L6562 (PFC), DAS01A, DLA001 (PWM Push-pull), DAP011 (PWM Flyback) microcircuits.
MainBoard - the main board (motherboard) is a KD890 module, using TDA8931T chips and others.
Tuner XD890WJN QPWBND984WJN1 provides the reception of television programs and tuning to channels.
LCD TV SHARP LC-42AD5RU with LCD, diagonal size 42 "(106 cm) in 16: 9 format. The brightness of the screen is 450 cd / m² by backlighting with CCFL fluorescent lamps (EEFL). Contrast as the ratio of maximum brightness to minimum not less than 1200: 1.
You can view images in high quality HD at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analogue systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i.
The power of the sound speaker system 20 W (2x10 W) provide two speakers. It uses a NICAM stereo signal processing system and Sound Surround.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x3, S-Video, SCART x2, RGB, VGA, HDMI x2, RS-232. An output for connecting headphones is provided. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector is used on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768.
A digital tuner is capable of receiving television channels in DVB-T standards.
The power consumed by the TV from the network in operating mode is 203 watts.
Overall dimensions: with stand 1036x736x292 mm, without stand 1036x677x134 mm.
TV Weight: with stand: 28 kg, without stand: 25.4 kg.
Attention! The LCD TV panel SHARP LC-42AD5RU is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!