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 LT1504S

Technical description and composition of the BBK LT1504S TV, panel type and applicable modules. The composition of the modules.
BBK
Model: LT1504S
Chassis / Version: MCT
Panel: SVA150XG04TB // SVA150XG10TB
Inverter (backlight): PP25P30107 cm BP // P05-AB0- P150TLTA3H // 730-703-150BTLTA-LH
PWM Inverter: TL494C (16)
MOSFET Inverter: APM4546 (8), 4501GSD
Trans Inverter: 730-703-150BTLTA
Power Supply (PSU): 200-001-XXXXTLTX-AH - 19-860-ABO-P150BTLTA-3H
PWM Power: LD7575PS (PWM flyback)
MOSFET Power: P9N70, D409, D405
MainBoard: 200-100-DK1694P-BH - 200-000-MS97885-S3H
IC MainBoard: MST97885LD / MST96885LD, AT24C32AN, 25L4005AMC, EM638165TS-66, TDA1517P, APA3541, WM8521HCGED
Tuner: JS-6H2 / 121 (TDA6509ATT)
Control: S0701244
Technical Specifications LT1504S
BBK LT1504S
General recommendations for repairing TV LCD
Possible malfunctions
- BBK LT1504S does not turn on at all and does not show any signs of operability. Does not blink indicators and does not respond to control buttons.
In such cases, the fault should be sought first in the power module 200-001-XXXXTLTX-AH. It is necessary to measure the secondary output voltage, and in case of their absence, check the serviceability of the power switches (P9N70, D409, D405) 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.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. PWM chip LD7575PS (PWM flyback) 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 and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
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. 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.
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 indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the 200-100-DK1694P-BH 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). Sometimes it is necessary to check or replace (if necessary) the elements of the MainBoard board - MST97885LD / MST96885LD, AT24C32AN, 25L4005AMC, EM638165TS-66, TDA1517P, APA3541, WM8521HCGED. In cases where the BGA processor is used, its malfunction is usually detected by local heating.
In the absence of tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltage at the terminals of the tuner JS-6H2 / 121 (TDA6509ATT). It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
Owners and users of the BBK LT1504S 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 / MANUAL ------------->   LT1504S, LT1904S, LT2004S

SCHEMATIC / MANUAL ------------->   BBK LT1504S, LT1904S, LT2004S (DK1594-TP0)
Service Manual with Schematic Diagram 35 pages 2006 on model LT1504S


 The appearance of the MainBoard 200-100-DK1694P-BH is shown in the figure below:
200-100-DK1694P-BH
200-100-DK1694P-BH can be used in TVs:
BBK LT1504S (Panel SVA150XG04TB), BBK LT2209S (Panel PV220WTVM).
The appearance of the power supply
Main features of the BBK LT1504S device:
Installed matrix (LCD panel) SVA150XG04TB or SVA150XG10TB.
The PP25P30107 inverter is used to power the backlight, controlled by the TL494C PWM controller (16). A transformer 730-703-150BTLTA is installed in the inverter converter. As power elements of the inverter, keys of the type APM4546 (8), 4501GSD are used.
The necessary supply voltages for all nodes of the TV BBK LT1504S are generated by the power module 200-001-XXXXTLTX-AH, or its analogs using microcircuits LD7575PS (PWM flyback) and power switches of the type P9N70, D409, D405.
MainBoard - the main board (motherboard) is a 200-100-DK1694P-BH module, using the MST97885LD / MST96885LD, AT24C32AN, 25L4005AMC, EM638165TS-66, TDA1517P, APA3541, WM8521HCGED and other chips.
The tuner JS-6H2 / 121 (TDA6509ATT) provides the reception of television programs and tuning to channels.
Information from an alternative source:
BBK LT1504S / BBK LT1904S, LT2004S, LT2209S (MST)
Motherboard: 200-100-DK1694P-BH, CPU - MST97885LD / MST96885LD (under the heatsink), Memory - AT24C32AN, Flash - 25L4005AMC, SDRAM - EM638165TS-66, Sound - TDA1517P, Tuner - JS-6H2 / 121 (TDA6509AT)
Panel Type (Matrix): SVA150XG04TB, Other ICs - APA3541, WM8521HCGED, Power & Inverter Board - 200-001-XXXXTLTX-AH, SMPS - LD7575PS, TR Chopper - 730-102-150BTLTA
Invertor: 730-703-150BTLTA-LH, Other ICs - 4501GSD, TL494C DIAGRAM BBK LT1504S
Additional technical information about the panel:
Brand: SVA-NEC
Model: SVA150XG04TB
Type: a-Si TFT-LCD, Panel
Diagonal size: 15.0 inch
Resolution: 1024x768, XGA
Display Mode: TN, Normally White, Transmissive
Active Area: 304.128x228.096 mm
Brightness: 250 cd / m²
Contrast Ratio: 450: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 60%
Response Time: 3/9 (Tr / Td)
Frequency: 60Hz
Lamp Type: 2 pcs CCFL Without Driver
Signal Interface: LVDS (1 ch, 8-bit), 20 pins
Voltage: 3.3V

 
LCD TV BBK LT1504S with LCD SVA150XG04TB, diagonal size 15 "4: 3 format. The brightness of the screen is 250 cd / m² backlight fluorescent lamps CCFL (EEFL). The ratio of maximum brightness to minimum (contrast) is 450: 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 acoustic system of sound 6 W (2x3W) 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. 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 48 watts.
Overall dimensions: 560x320x160 mm.
TV Weight: 5 kg.
Attention! The BBA LT1504S LCD TV panel SVA150XG04TB 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 05:22
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