REPAIRING AND NOT THROWING AWAY

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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Monday, 6 April 2020

REPAIR / SERVICING TV AKAI LTA-20A301

Technical description and composition of the AKAI LTA-20A301 TV, panel type and applicable modules. The composition of the modules.
AKAI
Model: LTA-20A301
Panel: A201SN01
Lamp backlight: 6 CCFL
Inverter (backlight): Inverter_6lamp_SCH.DDB
PWM Inverter: 1691SPW
MOSFET Inverter: ZXMP3A17E6, ZXMN3A03E6
Power Supply (PSU): 60W
PWM Power: NCP1377 (PWM flyback 8pin)
MOSFET Power: 10N60B
MainBoard: 20-MRTTV100
IC MainBoard: SAA7118, SAA5264, TDA7266D, LX1691CPW, AT24C16
Tuner: JS-6B2 / 121
Control: RM612
Technical Specifications LTA-20A301
AKAI LTA-20A301
General recommendations for repairing TV LCD
Possible manifestations of defects
- The AKAI LTA-20A301 TV does not turn on and does not show any signs of turning on. There are no reactions to the control buttons or the remote control.
Failure in such cases should be sought in the 60W power supply circuits. It is necessary to measure its secondary output voltages, and in case of their absence, check the serviceability of the power switches (10N60B) 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 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 the excess of maximum current or voltage values. It can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power key may be PWM (PWM) NCP1377 (PWM flyback 8pin). It is checked only by replacement with a known good one.
- 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.
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or the inverter.After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, you must ring in its converter power keys for breakdown and secondary windings of transformers for an open.
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 20-MRTTV100 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 chip replacement SAA7118, SAA5264, TDA7266D, LX1691CPW, AT24C16 are carried out with the necessary equipment, and the corresponding hardware base. Faults associated with the application of BGA processor soldering technologies can be localized by the heating method.
The malfunction of the tuner JS-6B2 / 121 is established after checking the software and all supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be controlled by an oscilloscope.
Owners and users of the AKAI LTA-20A301 TV should remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!


SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    AKAI LTA-20A301
 Key Features of the AKAI LTA-20A301:
Installed matrix (LCD panel) A201SN01.
To power the backlight, an Inverter_6lamp_SCH.DDB inverter is used, controlled by a 1691SPW PWM controller. As power elements of the inverter, keys of the type ZXMP3A17E6, ZXMN3A03E6 are used.
The necessary supply voltages for all nodes of the TV AKAI LTA-20A301 are generated by a 60W power module or its analogs using NCP1377 microcircuits (PWM flyback 8pin) and 10N60B type power switches.
MainBoard - the main board (motherboard) is a 20-MRTTV100 module, using chips SAA7118, SAA5264, TDA7266D, LX1691CPW, AT24C16 and others.
The JS-6B2 / 121 tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: A201SN01 V6
Type: a-Si TFT-LCD, Panel
Diagonal size: 20.1 inch
Resolution: 800x600, SVGA
Display Mode: TN, Normally White, Transmissive
Active Area: 408x306 mm
Surface: Antiglare, Antireflection
Brightness: 500 cd / m²
Contrast Ratio: 500: 1
Display Colors: 16.7M (8-bit), CIE1931 75%
Response Time: 5/11 (Tr / Td)
Frequency: 60Hz
Lamp Type: 6 pcs CCFL Without Driver
Signal Interface: TTL (1 ch, 8-bit), 50 pins
Voltage: 5.0V

 Trademark: AKAI, Model: LTA-20A301.
Briefly from the TV: LCD, 20 ", 800x600, sound: 6 watts.
The composition uses MainBoard 20-MRTTV100 and LCD-panel (matrix) A201SN01.
Power Supply Unit (PSU) 60W Power Supply.
AKAI LTA-20A301 TV with an A201SN01 LCD display, diagonal size 20 "in 4: 3 format. Screen brightness of 500 cd / m² is ensured by backlighting with CCFL (EEFL) fluorescent lamps. The ratio of maximum brightness to minimum (contrast) is 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 speaker system of sound 6 W (3 W x 2) provide 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, SCART, RGB, VGA. 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.
The power consumed by the TV working in the network mode is 60 watts.
Overall dimensions: With stand 820x620x250 mm, Without stand 820x560x110 mm.
TV mass: 12 kg.
Attention! The AKAI LTA-20A301 LCD TV panel A201SN01 is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!
Posted By: FRANK at 05:59
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