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 LT1911S

Technical description and composition of the BBK LT1911S TV, panel type and applicable modules. The composition of the modules.
BBK
Model: LT1911S
Chassis / Version: MS97885
Panel: M190A1-P0A PV190WTVM C08H
Inverter (backlight): integrated into PSU
PWM Inverter: TL494C (16)
MOSFET Inverter: 4501GSВ (8)
Trans Inverter: 730-703-2200TLTAH HL
Power Supply (PSU): ETL-XPC-204
PWM Power: LD7375PS (8)
MOSFET Power: P9NK70ZFP
MainBoard: 200-000-MS97885-S3H
IC MainBoard: WN8521HCQE, CM2021-00TR, 24C032, 25L4005AMC, AP334
Tuner: JS-6H2-121
Technical Specifications LT1911S
BBK LT1911S
General recommendations for repairing TV LCD
Possible manifestations of defects
- The BBK LT1911S TV does not turn on. There are no signs of operability. The indicators on the front panel do not shine and do not blink, and the remote control and control buttons do not respond.
With such manifestations, a malfunction is most likely to be detected in the ETL-XPC-204 power supply module. It is necessary to measure its secondary output voltages, and if they are absent, check the operability of the power switches (P9NK70ZFP) 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.
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 (LDW) LD7375PS (8). It is checked only by replacement with a known good one.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and disappears.
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, 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 turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the 200-000-MS97885-S3H 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). 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 WN8521HCQE, CM2021-00TR, 24C032, 25L4005AMC, AP334 and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
If a JS-6H2-121 tuner is suspected of malfunction, first of all, it is necessary to verify the correctness of the software, as well as the presence of the necessary supply voltage levels and data exchange pulses with the processor via the I2C bus on the corresponding tuner pins.
For LT1911S TV owners, we recommend that you contact qualified personnel with the necessary work experience for repairs! Self-repair attempts without the appropriate knowledge and skills can lead to irreversible negative consequences!
BBK LT1511S, LT1911S, LT2011S (BF1692-TP1)

PSU: ETL-XPC-204 CQC04001009066 200-001XXXXTLTX-BH 190DTLTD-SH


Service Manual with Schematic Diagram 36 pages 2006 on model LT1511S, LT1911S, LT2211S


 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 LT1911S device:
Installed matrix (LCD panel) M190A1-P0A PV190WTVM C08H.
To power the backlight, a converter is used, combined with a power supply, controlled by a TL494C PWM controller (16). The transformer 730-703-2200TLTAH HL is installed in the inverter converter. As power elements of the inverter, keys of type 4501GSВ are used (8).
The necessary supply voltages for all nodes of the TV BBK LT1911S are generated by the ETL-XPC-204 power module or its analogs using LD7375PS microcircuits (8) and power switches of the P9NK70ZFP type.
MainBoard - the main board (motherboard) is a 200-000-MS97885-S3H module, using microcircuits WN8521HCQE, CM2021-00TR, 24C032, 25L4005AMC, AP334 and others.
The tuner JS-6H2-121 provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: M190A1-P0A
Type: a-Si TFT-LCD, CELL
Diagonal size: 19.0 inch
Resolution: 1440x900, WXGA +
Display Mode: TN, Normally White, Transmissive
Active Area: 408.24x255.15 mm
Surface: Antiglare (Haze 25%), Hard coating (3H)
Transmissivity: 5.6% (with Polarizer)
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit)
Response Time: 1.5 / 3.5 (Tr / Td)
Frequency: 60Hz
Signal Interface: LVDS (2 ch, 8-bit), 30 pins
Voltage: 5.0V
 BBK LT1911S LCD TV with M190A1-P0A LCD, 19 "(48 cm) diagonal 16:10 aspect ratio. 450 cd / m² screen brightness is provided by CCFL (EEFL) fluorescent lamps. Maximum brightness to minimum ratio (contrast) ) is 850: 1. It is possible to view images in high quality HD at a resolution of 1440x900 pixels in the standard for graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standard max 480i, 480p, 576i, 576p, 720p.
The power of the sound system 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 x3, S-Video, component, 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.
The power consumed by the TV in the operating mode from the network is 60 watts.
Overall dimensions: 458x404x162 mm.
Mass of the TV: 4.9 kg.
Attention! The BBK LT1911S LCD TV panel M190A1-P0A PV190WTVM C08H is the most expensive of its components.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!
Posted By: FRANK at 07:07
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