Friday 10 April 2020

REPAIR / SERVICING TV AKIRA LCT-27PBSTP

Technical description and composition of the AKIRA LCT-27PBSTP TV, type of panel and applicable modules. The composition of the modules.
AKIRA
Model: LCT-27PBSTP
Chassis / Version: 782-L27W18-6900 ORION LCD2714
Panel: V270W1-L04
Power Supply (PSU): 782-L27W18-200B
PWM Power: TNY265P (Standby), ML4800CS
MOSFET Power: FB11N50A, 11N60C3
MainBoard: 782-L27W18-150A, 782.L37W25-4000
IC MainBoard: SVP-EX52 / 7052-LF, K4D263238F-QC50, TVP5147, SI19011CLU, M30620SPGP, 24C32A1, 24LC21A, HEF4052BT, MSP 3410G BB V3, TPA3008D2, NJW1109
Tuner: JS-6B2 / 121A2 & JS-6B2 / 122A2
Control: RC-102-OL
Technical Specifications LCT-27PBSTP
AKIRA LCT-27PBSTP
General recommendations for repairing TV LCD
Possible manifestations of defects
- The AKIRA LCT-27PBSTP TV does not turn on, does not respond to the remote control and the control panel buttons, and does not blink with any indicators.
Most often, with such manifestations, the main power supply module 782-L27W18-200B is found to be faulty. It is necessary to measure the secondary output voltage, and in case of their absence, check the serviceability of the power switches (FB11N50A, 11N60C3) of the converters and rectifier diodes for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during a short circuit in the 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. It can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power key can be PWM (PWM) TNY265P (Standby), ML4800CS. It is checked only by replacement with a known good one.
- There is no image, there is sound, it responds to the remote. Or the image may appear for a second when turned on and immediately disappears.
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. After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, it is necessary to ring in its converter power keys for breakdown and secondary windings of transformers for an open.
Sometimes, for diagnostic purposes, inverter protection must be disabled. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- The indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the motherboard 782-L27W18-150A 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 SVP-EX52 / 7052-LF, K4D263238F-QC50, TVP5147, SI19011CLU, M30620SPGP, 24C32A1, 24LC21A, HEF4052BT, MSP 3410G BB V3 , TPA3008D2, NJW1109 and other possible defective components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
If the TV works normally from external devices, but does not tune into television channels, the tuner JS-6B2 / 121A2 & JS-6B2 / 122A2 may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Attention TV owners! Attempts to self-repair AKIRA LCT-27PBSTP are not recommended by the manufacturer and can lead to serious negative consequences!

SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    AKIRA LCT-27PBSTP


AKIRA LCT-27PBSTP, ORION LCD2714
Service mode:
Press MENU, then - / -, then 9, then 1, then 8. Successively one after another. Then enter the factory menu, press the SLEEP button to select the adjustment page. Exit the factory menu: press the MENU button


Key features of the AKIRA LCT-27PBSTP device:
Installed matrix (LCD panel) V270W1-L04.
The necessary supply voltages are generated for all nodes of the AKIRA LCT-27PBSTP TV by the 782-L27W18-200B power supply module or its analogs using TNY265P (Standby), ML4800CS microchips and power switches of the FB11N50A, 11N60C3 type.
MainBoard - the main board (motherboard) is a module 782-L27W18-150A, using microcircuits SVP-EX52 / 7052-LF, K4D263238F-QC50, TVP5147, SI19011CLU, M30620SPGP, 24C32A1, 24LC21A, HEF4052BT, VSP310300, BB310300 , NJW1109 and others.
The JS-6B2 / 121A2 & JS-6B2 / 122A2 tuner allows you to receive television programs and tune to channels.
Additional technical information about the panel:
Brand: CMO
Model: V270W1-L04
Type: a-Si TFT-LCD, Panel
Diagonal size: 27.0 inch
Resolution: 1280x720, WXGA
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 597.12x335.88 mm
Surface: Antiglare (Haze 40%), Hard coating (3H), Reflection 2.0% (Max.)
Brightness: 550 cd / m²
Contrast Ratio: 900: 1
Display Colors: 16.7M (8-bit), CIE1931 75%
Response Time: 8 (G to G)
Frequency: 60Hz
Lamp Type: 14 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V

Brand: AKIRA, Model: LCT-27PBSTP.
Briefly from the TV: LCD, 27 ", 1280x720, 720p HD, there is PIP, there is a satellite tuner, sound: 12 watts.
The composition uses MainBoard 782-L27W18-150A, 782.L37W25-4000 and LCD panel (matrix) V270W1-L04.
Power Supply Unit (PSU) 782-L27W18-200B Power Supply.
AKIRA LCT-27PBSTP TV with V270W1-L04 LCD, 27 "diagonal size, 16: 9 format. 550 cd / m² screen brightness is provided by CCFL (EEFL) lamps. Contrast - the ratio of maximum brightness to minimum is at least 900: 1 It is possible to view in high quality HD at a resolution of 1280x720 pixels in 720p (HD Ready), the input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC.
The power of the sound system 12 W (2x6 W) provides two speakers. The audio processing system NICAM STEREO is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, S-Video, component, SCART, RGB, HDMI.
Overall dimensions: With stand 731x468x166 mm, Without stand 731x437x87 mm.
Attention! The AKIRA LCT-27PBSTP LCD TV panel V270W1-L04 is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!