Technical description and composition of the AKAI LCT2662 TV, type of panel and applicable modules. The composition of the modules.AKAI
Model: LCT2662
Panel: V270W1-L03
Power Supply (PSU): 27POWER300.PCB
PWM Power: NCP1377DR2 (PWM flyback 8pin), MC33260D (PFC), NCP1203P60 (Standby)
MOSFET Power: FQP18N50, STW12NK80Z, FQP7N80
Mainboard: MTV-2701
IC MainBoard: PW1230, PW113, VPC3230D, 24C16, K4S641632C, AD9883A, 29LV800D
Tuner: JS-6B3121 / F2
Control: E7501-051001 & E7501-051004
Specifications
AKAI LCT2662
General recommendations for repairing TV LCD
Possible malfunctions
- The AKAI LCT2662 TV does not turn on at all. There is no reaction to the remote control or to the control buttons from the front panel. Indicator lights do not light or flash.
Usually, with such manifestations, the defect is caused by faulty elements in the main power module 27POWER300.PCB. It is necessary to measure the secondary output voltages, and in case of their absence, check the serviceability of the power switches (FQP18N50, STW12NK80Z, FQP7N80) 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 short circuit in the elements of the primary circuit, the mains fuse usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power supply, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. PWM chip NCP1377DR2 (PWM flyback 8pin), MC33260D (PFC), NCP1203P60 (Standby) can also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it 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. 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, 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 TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the MTV-2701mainboard 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). Board repair and replacement of PW1230, PW113, VPC3230D, 24C16, K4S641632C, AD9883A, 29LV800D microcircuits are carried out with the necessary equipment, and the corresponding element base. Faults associated with the application of BGA processor soldering technologies can be localized by the heating method.
Before changing the JS-6B3121 / F2 tuner, if it is not possible to tune to television channels, make sure that there are supply voltages that must be measured at the corresponding tuner pins and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Once again, remind users! Attempts to self-repair a TV AKAI LCT2662 without the appropriate qualifications and necessary experience can lead to its complete non-repairability!
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> AKAI LCT2662
According to the conditions of compliance with modern world standards for household switching power supplies, the 27POWER300.PCB module provides for the use of a Power Factor Correction unit. The PFC circuit is a flyback converter based on the MC33260D PWM controller. The reactance of the electrolytic capacitor of the 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.
Key Features of the AKAI LCT2662:
Installed matrix (LCD panel) V270W1-L03.
The required supply voltages for all nodes of the TV AKAI LCT2662 are generated by the 27POWER300.PCB power module or its analogs using NCP1377DR2 (PWM flyback 8pin), MC33260D (PFC), NCP1203P60 (Standby) microcircuits, and power switches of the FQP18N50, STW12NK80Z, FQPP type.
MainBoard - the main board (motherboard) is an MTV-2701 module, using PW1230, PW113, VPC3230D, 24C16, K4S641632C, AD9883A, 29LV800D and other chips.
The tuner JS-6B3121 / F2 provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: CMO
Model: V270W1-L03
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 (2H), Reflection 2.0% (Max.)
Brightness: 500 cd / m²
Contrast Ratio: 900: 1
Display Colors: 16.7M (8-bit), CIE1931 75%
Response Time: 15/10 (Tr / Td); 16.6 (G to G)
Frequency: 60Hz
Lamp Type: 14 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 5.0V
