REPAIRING AND NOT THROWING AWAY

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and technical information about Service Modes, Circuit Diagrams, Firmware Update procedure, Disassemble procedure, Universal remote control set-up codes, Troubleshooting and more....

If you go into the profession, you will obtain or have access to a variety of tech tips databases HERE IT IS Master Electronics Repair !.

These are an excellent investment where the saying: 'time-is-money' rules. However, to learn, you need to develop a general troubleshooting approach - a logical, methodical, method of narrowing down the problem. A tech tip database might suggest: 'Replace C536' for a particular symptom. This is good advice for a specific problem on one model. However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for your sick TV or VCR.

While schematics are nice, you won't always have them or be able to justify the purchase for a one-of repair. Therefore, in many cases, some reverse engineering will be necessary. The time will be well spent since even if you don't see another instance of the same model in your entire lifetime, you will have learned something in the process that can be applied to other equipment problems.
As always, when you get stuck, checking out a tech-tips database may quickly identify your problem and solution.In that case, you can greatly simplify your troubleshooting or at least confirm a diagnosis before ordering parts.

Happy repairing!
Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

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..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

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Friday 10 April 2020

REPAIR / SERVICING TV AKIRA LCT-D26MT02ST

Technical description and composition of the TV AKIRA LCT-D26MT02ST, type of panel and applicable modules. The composition of the modules.
AKIRA
Model: LCT-D26MT02ST
Chassis / Version: MSDV2601-ZC01-01_C
Panel: V260B1-L02 Rev. C1 // V260B1-L03 // V260B1-L04
Inverter (backlight): VIT70038.50 REV: 3
PWM Inverter: OZ964SN
MOSFET Inverter: BH6N1A, BE6N33
Power Supply (PSU): MLT666 REV: 2.8
PWM Power: MC0628R, L6562D (PFC), OB2262 (PWM SOT23-6 62719)
MOSFET Power: 18N50, 6N60C
MainBoard: DVD DV8202-ZC01-01 (A) SPHE8202L, D5888S, laser: SF-HD65
IC MainBoard: W25X40, 24C32, STA5405A, IS42S16100C1-7TL, EN25T80
Tuner: JC-6H2 / 121
Appearance
AKIRA LCT-D26MT02ST
General recommendations for repairing TV LCD
Possible manifestations of defects
- AKIRA LCT-D26MT02ST does not turn on, the indicators on the front panel do not light or flash. The TV does not respond to the control buttons and the remote control.
Most likely in this case, the main switching power supply (IIP) MLT666 is faulty. It is necessary to measure its secondary output voltage, and in case of their absence, check the health of the power switches (18N50, 6N60C) 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.
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 MC0628R, L6562D (PFC), OB2262 (PWM SOT23-6 62719) can also cause a malfunction of the power switch of the converter and is checked by replacement.
- 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.
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.
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 during work, 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 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 DVD 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). If it is not possible to replace the MB board (SSB), you need to check the health of its elements - W25X40, 24C32, STA5405A, IS42S16100C1-7TL, EN25T80. Defective components should be replaced.
The malfunction of the JC-6H2 / 121 tuner is established after checking the software and all the supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be controlled by an oscilloscope.
Attention TV owners! Attempts at self-repair of AKIRA LCT-D26MT02ST are not recommended by the manufacturer and can lead to serious negative consequences!

SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    AKIRA Main MSDV2601

Panel restoration (matrix repair) ------------------>  V260B1-L04

 The MLT666 power module is installed in the LCT-D26MT02ST TV using the PFC (Power Factor Correction) scheme acting as an active filter to eliminate the higher harmonic components of the current consumption. The boost converter based on the L6562D PWM controller does not allow the input rectifier filter's electrolytic capacitor to be connected to the network directly through open diodes, when the reactance (about 15-30 ohms at a frequency of 50 Hz) determines the charge current. As a result of the conversion, the charging current of the capacitor will be determined in such a way that the envelope of the high-frequency pulses of the input current will repeat the phase and shape of the sine wave of the input voltage. The health check of the PFC unit is carried out by measuring the DC voltage on the capacitor of the rectifier network. In operating mode, it should be around 380V, in standby approximately 300V.
The appearance of the power supply
Key Features of the AKIRA LCT-D26MT02ST:
Installed matrix (LCD panel) V260B1-L02 Rev. C1 or V260B1-L03 or V260B1-L04.
To power the backlight, an inverter VIT70038.50 is used, it is controlled by the OZ964SN PWM controller. As power elements of the inverter, keys of the type BH6N1A, BE6N33 are used.
The required supply voltages for all nodes of the TV AKIRA LCT-D26MT02ST are generated by the MLT666 power module or its analogs using microchips MC0628R, L6562D (PFC), OB2262 (PWM SOT23-6 62719) and power switches of the type 18N50, 6N60C.
MainBoard - the main board (motherboard) is a DVD module using chips W25X40, 24C32, STA5405A, IS42S16100C1-7TL, EN25T80 and others.
The JC-6H2 / 121 tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: CMO
Model: V260B1-L02
Type: a-Si TFT-LCD, Panel
Diagonal size: 26.0 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 575.769x323.712 mm
Brightness: 450 cd / m²
Contrast Ratio: 800: 1
Display Colors: 16.2M (6-bit + FRC), CIE1931 72%
Response Time: 3/5 (Tr / Td)
Frequency: 60Hz
Lamp Type: 4 pcs CCFL Without Driver
Signal Interface: RSDS (1 Channel), 45 pins
Voltage: 5.3.3 / 5.0V (VDD / VIN5)