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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Friday 20 March 2020

REPAIR / SERVICING TV BBK LT2428S

Technical description and composition of the BBK LT2428S TV, panel type and applicable modules. The composition of the modules.
BBK
Model: LT2428S
Chassis / Version: //Ver1.0
Panel: V236H1-P01 // M236H1-P01
Inverter (backlight): LK-IN240404 VER 1.3
PWM Inverter: OB3316NQP (16)
MOSFET Inverter: ME4946 (8)
Power Supply (PSU): LK-OP1060-010
PWM Power: A7004 (8)
MOSFET Power: 6N60
MainBoard: CV7050LA 1002H0263
IC MainBoard: SPV7050P, Spi Flash: 25T80, Eeprom: 24C32, SOUND: TDA1517P
Tuner: F21WT-3BAR-E
Technical Specifications LT2428S
BBK LT2428S
General recommendations for repairing TV LCD
Possible manifestations of defects
- BBK LT2428S TV does not turn on, does not respond to the remote control and control panel buttons, does not blink with any indicators.
Usually, with such manifestations, the defect is caused by faulty elements in the main power module LK-OP1060-010. It is necessary to measure the secondary output voltages, and in case of their absence, check the serviceability of the power switches (6N60) 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 main 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 switch may be PWM (PWM) A7004 (8). It is checked only by replacement with a known good one.
- 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 supply module, or by inverter defects, as well as by 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 the power switches for breakdown and the secondary windings of the transformers for an open.
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 when working, 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 turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the CV7050LA 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 chips SPV7050P, Spi Flash: 25T80, Eeprom: 24C32, SOUND: TDA1517P 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 replacing the F21WT-3BAR-E tuner, if there is no tuning for the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus
Owners and users of the BBK LT2428S 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!

 Service Manual with Schematic Diagram (DOC) 29 pages 2009 on model LT1526S, LT2428S



Repair MainBoard
The appearance of the MainBoard CV7050LA is shown in the figure below:
CV7050LA
CV7050LA can be used in TVs:
BBK LT1902S (Panel M190A1-P0A), BBK LT2202S (Panel M216H1-P01), BBK LT2428HD (Panel V236H1-P01 HK236WLCM-CH03H), BBK LT2428S (Panel V236H1-P01), FUSION FLTV-19W6 (Panel M190A1-P0A), IZUMI TL26H615B (Panel M260TWR1).
Main features of the BBK LT2428S device:
Installed matrix (LCD panel) V236H1-P01 or M236H1-P01.
To power the backlight, an inverter LK-IN240404 is used, it is controlled by the PWM controller OB3316NQP (16). As power elements of the inverter, keys of the type ME4946 (8) are used.
The necessary supply voltages for all nodes of the TV BBK LT2428S are generated by the power module LK-OP1060-010, or its analogs using A7004 microcircuits (8) and power switches of the 6N60 type.
MainBoard - the main board (motherboard) is a CV7050LA module, using chips SPV7050P, Spi Flash: 25T80, Eeprom: 24C32, SOUND: TDA1517P and others.
The F21WT-3BAR-E tuner provides television reception and channel tuning.


Additional technical information about the panel:
Brand: CMO
Model: V236H1-P01
Type: a-Si TFT-LCD, CELL
Diagonal size: 23.6 inch
Resolution: 1920x1080, FHD
Display Mode: TN, Normally White, Transmissive
Active Area: 521.28x293.22 mm
Surface: Antiglare (Haze 25%), Hard coating (3H)
Glass Depth: 0.70 + 0.70 mm
Contrast Ratio: 800: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 72%
Response Time: 1.5 / 3.5 (Tr / Td)
Frequency: 60Hz
Signal Interface: LVDS (2 ch, 8-bit), 30 pins
Voltage: 5.0V


BBK LT2428S LCD TV with V236H1-P01 LCD, 24 "(61 cm) diagonal size in 16: 9 format. 300 cd / m² screen brightness is provided by CCFL (EEFL) fluorescent lamps. Maximum brightness to minimum ratio (contrast) ) is 700: 1. The design and technical capabilities of the TV provide for viewing broadcasts and films in high quality HD at a resolution of 1920x1080 pixels in graphic decomposition according to the standard 1080p (Full HD). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC Graphic Digital signal processing and generation takes place in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p.
The power of the acoustic system of sound 6 W (2x3 W) 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, audio x2, S-Video, SCART, RGB, VGA, HDMI. An output for connecting headphones is provided. 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, 1024x768, 1360x768.
The power consumed by the TV in the operating mode from the network is 70 watts.
Overall dimensions: With a support 580x451x240 mm, Without a support 580x402x79 mm.
TV Weight: 5.8 kg.
Attention! The BBK LT2428S LCD TV panel V236H1-P01 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 08:48
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