Technical description and composition of the TV SHARP LC-20V1RU-BK, type of panel and applicable modules. The composition of the modules.SHARP
Model: LC-20V1RU-BK
Panel: LK197V3GZ91
Inverter (backlight): CEF279A ETL-XPC-204T
MOSFET Inverter: C5886A
Trans Inverter: V18 089II
Power Supply (PSU): ETL-XPC-204T CEF279A
PWM Power: STR-W6765, LA5779
MainBoard: CMF102B 4
IC MainBoard: VCT6773G B3 000, 24C256BN, KE454U2380, BD8139AEFV, LA42052, LA5779
Tuner: TAFV-W323D
Control: LCDTV 010240 (LCDTV 010150)
Technical Specifications LC-20V1RU
SHARP LC-20V1RU-BK
General recommendations for repairing TV LCD
It is advisable to start diagnosing a malfunction of the SHARP LC-20V1RU-BK TV, like all others, with an external examination of possible changes, both external and internal elements. Visible damage to elements can sometimes suggest further directions for finding a defect before starting the necessary measurements. Carbonized paint on the upper layer of resistors, electrolytic capacitors of rectifier filters swollen after boiling, cracked soldering at the terminals of heating elements or transformers can often suggest the cause of the defect and possible consequences.
Sometimes the SHARP LC-20V1RU-BK TV simply does not turn on. No control lights on the front panel are lit or blinking, the TV does not respond to the remote control and does not make any sounds or any signs of life when turned on. The most likely cause of the malfunction is the failure of the ETL-XPC-204T CEF279A Common Power Module. If the mains fuse is broken in the power supply, in most cases a breakdown of the power switch is detected, which can be integrated with the PWM controller, or a separate field-effect transistor can be used. The rectifier bridge diodes and the electrolytic capacitor of the mains rectifier filter should also be checked.
The reasons for the breakdown of the power switch of the flyback converter of the power supply module can be different, for example, a malfunction of semiconductor cells or electrolytic capacitors in the stabilization circuits of the primary circuit, as well as a failure in the operation of the PWM controller chip STRW6765, LA5779 or breakage of the resistors in its bundle.
If the power module uses an active KKM circuit (power factor control), troubleshooting is somewhat more complicated.
If there is no image when you turn on the SHARP LC-20V1RU-BK, or it appears for a second and disappears completely, but there is sound, most likely either the backlight or their power converter (inverter) are faulty. It is necessary to check the electrolytic capacitors of the filter of the secondary rectifiers in the general power supply unit.
Often, attempts to repair the CEF279A ETL-XPC-204T inverter are hampered by the fact that the diagnosis of the malfunction is complicated by the operation of its protection, which is designed to turn off the inverter in emergency conditions - when the lamps are depressurized, breaks or short circuits in high-voltage connections and other emergency situations. Lock protection to localize the defect is popular among repairmen.
In such cases, the risk of failure of the power elements of the inverter is most likely, and special care is required during work, and after their completion, it is necessary to restore the protection circuit for further safe operation of the TV by the owner in normal mode.
Repair of the CMF102B 4 motherboard must begin with the diagnosis and verification of all linear stabilizers or power converters of its microcircuits. Sometimes it may be necessary to update the software (software) - flashing FLASH or EEPROM.
If the TV works normally from external devices, but does not tune into television channels, the TAFV-W323D tuner 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).
We recommend the owners of the LC-20V1RU-BK TV for repair only to qualified specialists with experience! Self-repair attempts without the appropriate knowledge and skills can lead to serious negative consequences!
Service manual / schematic diagram ------------> LC-20V1RU-BK
Service Manual with Schematic Diagram 24 pages model LC-20V1RU-BK, LC-20V1RU-WH.
The appearance of the MainBoard CMF102B is shown in the figure below:CMF102B
CMF102B can be used in TVs:
SHARP LC-20S5E-BK (Panel LK197V3GZ91), SHARP LC-20V1RU-BK (Panel LK197V3GZ91).
The appearance of the power supply
Main features of the SHARP LC-20V1RU-BK device:
Installed matrix (LCD panel) LK197V3GZ91.
To power the backlight used inverter CEF279A. The transformer V18 089II is installed in the inverter converter. As power elements of the inverter, keys of the type C5886A are used.
The necessary supply voltages for all nodes of the SHARP LC-20V1RU-BK TV are generated by the ETL-XPC-204T power supply module or its analogs using STR-W6765, LA5779 microcircuits.
MainBoard - the main board (motherboard) is a CMF102B module, using VCT6773G B3 000, 24C256BN, KE454U2380, BD8139AEFV, LA42052, LA5779 and other chips.
The TAFV-W323D tuner provides TV reception and channel tuning.
LCD TV SHARP LC-20V1RU with LCD LK197V3GZ91, diagonal size 20 "4: 3 format. The brightness of the screen 430 cd / m² is organized by backlighting with CCFL fluorescent lamps (EEFL). Contrast, as the ratio of maximum brightness to minimum, not less than 500: 1. The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation takes place in the standards 480i, 480p, 576i, 576p.
The power of the sound system 4 W (2x2W) 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 x2, audio x2, S-Video, component, RS-232. An output for connecting headphones is provided.
The power consumed by the TV from the network in operating mode is 74 watts.
Overall dimensions: with stand 478x434x225 mm, without stand 478x400x89 mm.
TV mass: with stand: 6.2 kg, without stand: 5.4 kg.
Attention! The LK197V3GZ91 panel of the SHARP LC-20V1RU LCD TV is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!