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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Tuesday 24 March 2020

REPAIR / SERVICING TV BBK LED2253FW

Technical description and composition of the BBK LED2253FW TV, type of panel and applicable modules. The composition of the modules.
BBK LED
Model: LED2253FW
Chassis / Version: S227NZ1NRJ20C
Panel: M215ED1DA3-1
LED driver (backlight): CEM-1 F782018223
PWM LED driver: 8pin
Power Supply (PSU): CEM-1 F782018223
PWM Power: PWM SOT23-6
MainBoard: 29T1291 88XR-MCEZ1B02273FW E128-VG-Z1-B0
IC MainBoard: YD1517P, RT7237AN (8)
Control: RC-LED101
Technical Specifications LED2253FW
BBK LED2253FW
General repair guidelines for TV LCD LED
Possible malfunctions
- The BBK LED2253FW TV does not turn on and does not show any sign of turning on at all. There are no reactions to the control buttons or the remote control.
In most of these cases, the CEM-1 main switching power supply is faulty. 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 short circuit in the power 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, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. PWM SOT23-6 PWM 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 commands from the remote control. Or the image appears immediately after turning on and disappears.
As a rule, in such cases there is no display backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the LED line for breaks without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally, a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters, as a rule, light up a single 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as a health indicator. In faulty LEDs, the zener diode will either be cut off or broken into short-circuit.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the 29T1291 motherboard should begin by checking the stabilizers and power converters needed to power the microcircuit and matrix. If necessary, update or replace the software (software). If it is not possible to replace the MB (SSB) card, it is necessary to check the health of its elements - YD1517P, RT7237AN (8). Defective components should be replaced.

Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Entrust repair to professionals with sufficient experience in the field of repair of electronic equipment.

 Service Manual with Schematic Diagram 32 pages on the model LEM1993, LED1994, LEM1995, LEM1996, LEM1997, LEM2293F, LED2294F, LEM2295F, LEM2296F, LEM2297F, LEM2493F, LED2494F, LEM2495F, LEM2496F, LEM2497F, LEM2993, LED2994, LEM2995, LEM2996, LEM2997, LED2253FW, LED1952DTG, LED2252FDTG, LED2452FDTG, LED2278F.






Main features of the BBK LED2253FW device:
Installed matrix (LED-panel) M215ED1DA3-1.
The LED driver CEM-1 is used to power the backlight LEDs, it is controlled by a 8pin PWM controller.
The necessary supply voltages for all nodes of the TV BBK LED2253FW are generated by the CEM-1 power module or its analogs using PWM SOT23-6 microcircuits.
MainBoard - the main board (motherboard) is a 29T1291 module, using YD1517P, RT7237AN (8) microcircuits and others.

Brand: BBK, Model: LED2253FW.
Briefly from the TV: LCD, 1080p Full HD, diagonal 22 "(56 cm), HDMI: 2, USB, backlight type: Edge LED.

The composition uses MainBoard E182VG-Z1-B0 and an LCD panel (matrix) M215ED1DA3-1.
Power Supply Unit (PSU) CEM-1 F782018223 Power Supply.
 
 
BBK LED TV LED2253FW with M215ED1DA3-1 LCD display, diagonal size 22 "(56 cm) 16: 9 format. The required brightness of the screen is 250 cd / m² LED backlight LED. The ratio of maximum brightness to minimum (contrast) is 800 : 1. This model uses Edge LED backlighting, and the design and technical features of the TV include watching broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphic resolution according to the standard 1080p (Full HD). Input high-frequency or video signal l can be processed in analogue systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, MKV, VideoCD , SVCD, Picture CD, JPEG.
The power of the acoustic system of sound 6 W (2x3 W) provide two speakers. It uses a NICAM stereo signal processing system and Sound Surround.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, VGA, HDMI x2, USB. 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, 1280x1024, 1360x768, 1920x1080.

Overall dimensions: With stand 550x405x125 mm, Without stand 498x371x83 mm.

TV Weight: 4.5 kg.

Attention! The M215ED1DA3-1 panel of the BBK LED2253FW LED TV is an expensive and unreliable element.
Avoid any impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also unsafe to get liquid on the screen. Sometimes one drop is enough if it flows down the glass onto the cables so that the TV becomes unrepairable.
Posted By: FRANK at 06:03
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