Technical description and composition of the SHARP LC-42X20 TV, panel type and applicable modules. The composition of the modules.SHARP
Model: LC-42X20 LC-42X20E
Chassis / Version: KE186
Panel: LK420D3LZ50Y
T-CON: CPWBX3829TPXD
Inverter (backlight): RUNTKA319WJZZ ISP013-01 PCB2839 A06-227597C, RUNTKA320WJZZ ISP013-01 PCB2840 A06-227598B
Power Supply (PSU): DPS-304BP RDENCA231WJQZ CA231WJQZ A38W0809029475
PWM Power: L6562DTR, DLA001DTR, LA5774, TNY266PN
MainBoard: DUNTKE186WE + DUNTKE187WE
IC MainBoard: K4N56163QI, SIL9185ACTU
Tuner: TDQG4-003A
Control: IR: NE264WJ KE264
Technical Specifications LC-42X20RU
SHARP LC-42X20
General recommendations for repairing TV LCD
Possible malfunctions
- The SHARP LC-42X20 TV does not turn on, does not respond to the remote control and buttons on the control panel, does not light up or blink indicators.
Most likely in this case, the main switching power supply (IIPS) DPS-304BP is faulty. It is then necessary to measure its output voltages and, if they are absent, it is necessary to check the power switches and rectifier diodes of the converters for a short-circuit probability.
In case of breakdowns of semiconductors in the secondary circuits, the converter can usually work abnormally in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse often breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM) L6562DTR, DLA001DTR, LA5774, TNY266PN, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn on and immediately disappears.
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or the inverter.After checking all the electrolytic capacitors of the filters that are involved in the power supply to the inverter, you must ring in its converter power keys for breakdown and secondary windings of transformers for an open.
If in diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required when working, and after they are finished, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the DUNTKE186WE motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). Sometimes it is necessary to check or replace (if necessary) the elements of the MainBoard board - K4N56163QI, SIL9185ACTU. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
In the absence of tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltage at the terminals of the TDQG4-003A tuner. It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
We recommend the owners of the LC-42X20 TV for repair only to qualified specialists with the necessary work experience! Self-repair attempts without the appropriate knowledge and skills can lead to irreversible negative consequences!
Service manual / schematic diagram -------------------> SHARP LC-42X20 Chassis KE186 LC-42X20E, LC-42X20S, LC-42X20RU
PSU / schematic diagram -------------------> DPS-304BP Power supply
The appearance of the MainBoard DUNTKE186WE is shown in the figure below:DUNTKE186WE
The appearance of the power supply
Main features of the SHARP LC-42X20 device:
Installed matrix (LCD panel) LK420D3LZ50Y.
The matrix control uses the Timing Controller (T-CON) CPWBX3829TPXD.
To power the backlight used inverter RUNTKA319WJZZ.
The necessary supply voltages for all nodes of the SHARP LC-42X20 television are generated by the DPS-304BP power supply module or its analogs using the L6562DTR, DLA001DTR, LA5774, TNY266PN microcircuits.
MainBoard - the main board (motherboard) is a DUNTKE186WE module, using K4N56163QI, SIL9185ACTU chips, and others.
The TDQG4-003A tuner provides TV reception and channel tuning.
LCD TV SHARP LC-42X20RU with an LCD display, diagonal size 42 "(106 cm) in 16: 9 format. The brightness of the screen is 450 cd / m² by CCFL (EEFL) fluorescent lamps. Contrast as the ratio of maximum brightness to minimum , not less than 2000: 1. Dynamic contrast ratio of 10000: 1 is achieved by controlling the backlight depending on the brightness of the plot.
The design and technical capabilities of the TV include watching programs and movies in high quality HD at a resolution of 1920x1080 pixels in a graphical decomposition according to the standard 1080p (Full HD). The input high-frequency or video signal can be processed in analogue systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p.
The power of the speaker system of sound 30 W (2x15W) 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 x4, S-Video, component, SCART x2, RGB, VGA, HDMI x3, 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, 1280x1024, 1360x768.
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 208 watts.
Overall dimensions: with stand 1004x708x305 mm, without stand 1004x646x95 mm.
TV Weight: with stand: 26 kg, without stand: 21.5 kg.
Attention! The LCD TV panel SHARP LC-42X20RU is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!
