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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Tuesday 24 March 2020

REPAIR / SERVICING TV BBK LED2475FDT

Technical description and composition of the BBK LED2475FDT TV, type of panel and applicable modules. The composition of the modules.
BBK LED
Model: LED2475FDT
Chassis / Version: L0M05 (01)
Panel: LC230EUE (TD) (A1)
LED driver (backlight): integrated into PSU
Power Supply (PSU): FSE060E0 F782003311
PWM Power: LD7535 (PWM 6 pin)
MainBoard: L0M05 (01)
IC MainBoard: MSD309PX-LF, PFC567ZD46B, W9751G6JB-25, 61337B200022147WMA, MP1482DS, B883874S, 25Q32BVS1G
Tuner: R620D
Control: RCLED100
Technical Specifications LED2475FDT
BBK LED2475FDT
General repair guidelines for TV LCD LED
Possible manifestations of defects
- BBK LED2475FDT 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.
In the vast majority of such cases, a malfunction is detected in the FSE060E0 power module. It is necessary to measure its secondary output voltages, 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 a 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 key may be PWM (PWM) LD7535 (PWM 6 pin). 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.
Often in such cases, there is no LED backlight. The reason can be both in the power of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
It should be remembered that it is not possible to determine the open circuit in the LED lines without disassembling the panels with a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then it is necessary to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow you to open the LED in the forward direction or dual LEd are used, then the PN junction of the emergency zener diode can indirectly serve as a health indicator. In case of LED-a failure, the zener diode PN junction will either be cut off or broken into short-circuit.
- 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 L0M05 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 - MSD309PX-LF, PFC567ZD46B, W9751G6JB-25, 61337B200022147WMA, MP1482DS, B883874S, 25Q32BVS1G. 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 R620D tuner. 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.
Attention! For users and owners of LED2475FDT TVs who do not have the appropriate qualifications, knowledge and experience, we categorically do not recommend attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.


SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>   BBK LED1975, LED2275F, LED2475F, LEM1988, LEM2288F, LEM2488F (MST6M182VG + 2IN1 POWER SUPPLY)


The appearance of the MainBoard L0M05 is shown in the figure below:
The MainBoard L0M05 uses the MSD309B processor, a BGA-based DDRAM random access memory (RAM) and an SPI Flash ROM of type 25Q32 (4Mb).
It is advisable to start repairing the motherboard by checking the voltage converters and linear stabilizers necessary to provide power to the nodes in operating and standby mode. The processor core is powered by + 1.5V. Also, the processor voltage requires + 2.5V and + 3.3V.
If the display backlight is OK and there is no image, it is necessary to check the panel power (depending on the type, + 5V or + 12V), which is more convenient to measure directly on the LVDS connector. If, in the presence of all the supply voltages, the TV does not enter the operating mode, does not respond to the Remote Control and control buttons, update the SPI Flash firmware.
L0M05 can be used in TVs:
BBK LED1955DT (Panel V185B1-LE1 Rev.C1), BBK LED2275FDT (Panel V215H1-LE1 REV.C1), BBK LED2475FDT (Panel LC230EUE (TD)(A1)), BBK LEM1968DT Ver1 (Panel V185B1-LE1 Rev.C1), BBK LEM2488FDT (Panel LC230EUE), BBK LEM1988DT (Panel V185B1-LE1 Rev.C1 CMO), BBK LED2455FDT (Panel LC230EUE (TD)(A1)).
The appearance of the power supply
Main features of the BBK LED2475FDT device:
Installed matrix (LED-panel) LC230EUE (TD) (A1).
To power the backlight LEDs, a converter is used, combined with a power supply.
The necessary supply voltages are generated for all nodes of the BBK LED2475FDT TV by the FSE060E0 power module, or its analogs using LD7535 microcircuits (PWM 6 pin).
MainBoard - the main board (motherboard) is an L0M05 module, using microchips MSD309PX-LF, PFC567ZD46B, W9751G6JB-25, 61337B200022147WMA, MP1482DS, B883874S, 25Q32BVS1G and others.
The R620D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC230EUE-TDA1
Type: a-Si TFT-LCD, Panel
Diagonal size: 23.0 inch
Resolution: 1920x1080, FHD
Display Mode: TN, Normally White, Transmissive
Active Area: 509.184x286.416 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 250 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit)
Response Time: 1.3 / 3.7 (Tr / Td)
Frequency: 60Hz
Lamp Type: 2 strings WLED Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 30 pins
Voltage: 5.0V