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 LT1915S

Technical description and composition of the BBK LT1915S TV, panel type and applicable modules. The composition of the modules.
BBK
Model: LT1915S
Panel: HT190WG1-101
Inverter (backlight): integrated into PSU
PWM Inverter: BIT3105
Power Supply (PSU): JSI-190411 I0050613 V1.05 S3110
PWM Power: SG5841SZ (SO8)
MainBoard: E-RSAG7.820.847A LCD1533EU
IC MainBoard: FLI8125-LF, TDA9886, MSP3410, TDA1517, 24C32, 39VF088, FLI8125-LF
Tuner: TDQ-6FT / W12GH
Control: WH 071023C
Appearance
BBK LT1915S
General recommendations for repairing TV LCD
Possible malfunctions
- The BBK LT1915S TV does not turn on, does not respond to the remote control and the control panel buttons, the indicators do not light or flash.
Often in such cases, the JSI-190411 power module is faulty. It is necessary to measure the secondary output supply voltage, and in case of their absence, check the serviceability of the power switches 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. The PWM chip 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
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.
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 turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the MAIN_PCB 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).
The TDQ-6FT / W12GH tuner malfunction 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.
TV users and owners need to remember that attempts to self-repair a BBK LT1915S TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
Service Manual / Schematic Diagram ---------------------->   LT1514S, LT1914S (HUDSON)


 The appearance of the MainBoard E-RSAG7.820.847A is shown in the figure below:
E-RSAG7.820.847A
E-RSAG7.820.847A can be used in TVs:
BBK LT1514S (Panel SVA150XG04), BBK LT1914S (Panel 19 inches 1440x900), BBK LT1915S (Panel HT190WG1-101).
The appearance of the power supply
Main features of the BBK LT1915S device:
Installed matrix (LCD panel) HT190WG1-101.
To power the backlight, a converter is used, combined with a power supply, controlled by a BIT3105 PWM controller.
The necessary supply voltages for all nodes of the BBK LT1915S TV are generated by the JSI-190411 power module or its analogs using SG5841SZ (SO8) microcircuits.
MainBoard - the main board (motherboard) is an E-RSAG7.820.847A module, using the chips FLI8125-LF, TDA9886, MSP3410, TDA1517, 24C32, 39VF088, FLI8125-LF and others.
The TDQ-6FT / W12GH tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: BOE
Model: HT190WG1-101
Type: a-Si TFT-LCD, Panel
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)
Brightness: 300 cd / m²
Contrast Ratio: 800: 1
Display Colors: 16.7M (6-bit + Hi-FRC)
Response Time: 1.5 / 3.5 (Tr / Td)
Frequency: 60Hz
Lamp Type: 4 pcs CCFL Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 30 pins
Voltage: 5.0V
Posted By: FRANK at 07:14
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