Technical description and composition of the TV SHARP LC-37RA1RU, type of panel and applicable modules. The composition of the modules.SHARP
Model: LC-37RA1RU
Chassis / Version: KD915
Panel: LK370T3LZ5BX
T-CON: CPWBX3348TPZ C
Inverter (backlight): RUNTKA244WJZZ MPV8A015, RUNTKA245WJZZ MPV8A016
Power Supply (PSU): DUNTKD787WE QPWBFD787WJN2
PWM Power: FA5501A (PFC), MR4040, MR4020
MOSFET Power: K3525
MainBoard: KD915 XD915WJN1 + QPWBXD628WJN2 + QPWBFD604WJN3
IC MainBoard: VGC5969B, SIL9023CTU, K4H561638H-UCB3, 24LC256, M29DW128F
Tuner: QPWBND833WJN1
Technical Specifications LC-37RA1RU
SHARP LC-37RA1RU
General recommendations for repairing TV LCD
Possible manifestations of defects
- The SHARP LC-37RA1RU TV does not turn on, does not respond to the remote control and control panel buttons, indicators do not light up and do not blink.
In some of these cases, the main switching power supply, the DUNTKD787WE module, is found to be faulty. It is necessary to verify the presence of its output voltages and, if they are completely absent, check the power switches (K3525) and rectifier diodes for a probable short circuit.
In case of breakdowns in the secondary circuits, the converter, as a rule, can emergency work in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse usually 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) FA5501A (PFC), MR4040, MR4020, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
These manifestations can be triggered by a power module, or by defects in the inverter, as well as a distortion of the currents in the lamps due to their uneven wear. If all the electrolytic capacitors of the filter according to the inverter power supply are serviceable, you should make sure that the lamps are working, then you need to check the converter keys and the secondary windings of the transformers.
Sometimes, for diagnostic purposes, it is necessary to disable the inverter protection. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- 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 KD915 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). 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 chips VGC5969B, SIL9023CTU, K4H561638H-UCB3, 24LC256, M29DW128F and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
Before replacing the tuner QPWBND833WJN1, if there is no tuning for the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus
TV users and owners must remember that attempts to self-repair a SHARP LC-37RA1RU TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
Service Manual with Schematic Diagram 186 pages 2007 model LC-32RA1E, LC-32RA1RU, LC-37RA1E, LC-37RA1RU.
The appearance of the MainBoard KD915 is shown in the figure below:KD915
The appearance of the power supply
Main features of the SHARP LC-37RA1RU device:
Installed matrix (LCD panel) LK370T3LZ5BX.
The matrix control uses the Timing Controller (T-CON) CPWBX3348TPZ.
RUNTKA244WJZZ inverter is used to power the backlight.
The necessary supply voltages for all nodes of the SHARP LC-37RA1RU TV are generated by the DUNTKD787WE power module or its analogs using FA5501A (PFC), MR4040, MR4020 microcircuits and K3525 type power switches.
MainBoard - the main board (motherboard) is a KD915 module, using VGC5969B, SIL9023CTU, K4H561638H-UCB3, 24LC256, M29DW128F and others.
The tuner QPWBND833WJN1 provides the reception of television programs and tuning to channels.
LCD TV SHARP LC-37RA1RU with an LCD display, diagonal size 37 "(94 cm) in 16: 9 format. The brightness of the screen is 450 cd / m² by backlighting with CCFL (EEFL) fluorescent lamps. Contrast as the ratio of maximum brightness to minimum , not less than 1200: 1. Dynamic contrast ratio of 3000: 1 is achieved by controlling the backlight depending on the brightness of the plot.
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.
Overall dimensions: with stand 920x657x291 mm, without stand 920x600x116 mm.
TV Weight: with stand: 25.3 kg, without stand: 22.6 kg.
Attention! The LCD TV panel SHARP LC-37RA1RU is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!