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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Thursday 27 August 2020

REPAIRING / SERVICING TV DNS V40DN54

Technical description and composition of the DNS V40DN54 TV, panel type and modules used. The composition of the modules.
DNS LED
Model: V40DN54
Chassis / Version: CV9202H-A
Panel: LTA400HM24
LED backlight: SLED 2012SLS40 7030 44 L / R REV1.2
LED driver (backlight): LK-LE420202D
Power Supply (PSU): LKP-SP006 REV: 1.1 LK-SP416002A
PWM Power: PWM SOT23-6 (OB2273)
MainBoard: CV9202H-A
IC MainBoard: SPI FLASH: W25Q32FV
Tuner: NoName
Specifications V40DN54
DNS V40DN54
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- DNS V40DN54 does not turn on, front panel LEDs are off or flashing. The TV does not respond to the control buttons and the remote control.
In some of these cases, a malfunction is detected in the LKP-SP006 power supply module. Its output voltages should be measured and, in their absence, the serviceability of the power switches and rectifier diodes in the converters should be checked for possible breakdown.
In case of any breakdowns in the secondary circuits, the converter can operate in an emergency mode of a short circuit, and with a short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key often breaks off.
Mos-Fet power switches used in switching power supplies sometimes fail due to a malfunction of any other elements that can disable it in the key mode, or create an excess of the maximum permissible key parameters. These can be elements supplying a PWM regulator, frequency setting or damper circuits, or elements of negative feedback in the stabilization circuit. PWM controllers, in the absence of visible damage or outright short circuits between the terminals, are checked by replacing them with new ones, or knowingly working properly.
- There is no picture, but there is sound, it reacts to the remote control. Or the image appears when turned on and immediately disappears
In some of these cases, the malfunction is caused by the lack of display backlighting. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
To check the LED strips for breakage without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter; a voltage of the order of several tens of volts is required.
- The TV does not turn on, the indicator signals the standby or operating mode, or blinks.
Repair or diagnostics of the CV9202H-A motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). If it is not possible to replace the MB (SSB) board, it is necessary to check the serviceability of its elements - SPI FLASH: W25Q32FV. Defective components must be replaced.

Users and owners of TVs need to remember that attempts to repair a DNS V40DN54 TV on their own without the appropriate qualifications and the necessary experience can lead to serious negative consequences!


DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   DNS V40DN54, Main: CV9202H-A, Panel: LTA400HM24

 The appearance of the MainBoard CV9202H-A is shown in the figure below:
CV9202H-A
Main features of the DNS V40DN54 device:
Installed matrix (LED-panel) LTA400HM24.
The LED driver LK-LE420202D is used to power the backlight LEDs.
The formation of the necessary supply voltages for all nodes of the DNS V40DN54 TV is carried out by the LKP-SP006 power supply module, or its analogs using PWM SOT23-6 (OB2273) microcircuits.
MainBoard - the main board (motherboard) is a CV9202H-A module, using SPI FLASH chips: W25Q32FV and others.
Tuner NoName provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTA400HM24
Type: a-Si TFT-LCD, Panel
Diagonal size: 40 inch
Resolution: 1920x1080, FHD
Display Mode: S-PVA, Normally Black, Transmissive
Active Area: 885.6x498.15 mm
Surface: Antiglare (Haze 0.8%), Hard coating (2H)
Brightness: 470 cd / m²
Contrast Ratio: 5000: 1
Display Colors: 1.07B (8-bit + Hi-FRC), CIE1931 70%
Response Time: 8 (G to G)
Frequency: 60Hz
Lamp Type: 2 strings WLED Without Driver
Signal Interface: LVDS (2 ch, 10-bit), 51 pins
Voltage: 12.0V
DNS V40DN54 TV with LCD LTA400HM24, diagonal 40 "(102 cm) in 16: 9 format. The required screen brightness of 400 cd / m² is provided by LED backlighting. Contrast - the ratio of maximum brightness to minimum brightness is 6000: 1. the model uses a panel with backlighting LEDs at the end - Edge LED.
The LTA400HM24 matrix and the MainBoard CV9202H-A software provide viewing of broadcasts and films in high quality HD at a resolution of 1920x1080 pixels in graphics resolution at 1080p (Full HD). The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Graphic processing and formation of a digital signal occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, WMA, MPEG4, DivX, MKV, JPEG.
Speaker power 20 W (2x10 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, SCART, VGA, HDMI x3, USB. A headphone output is provided. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector on the TV case is used, this interface supports resolutions: 640x480, 800x600, 1024x768, 1360x768, 1920x1080. The digital tuner is capable of receiving TV channels in DVB-C standards.
The power consumed by the TV operating in mains mode is 90 W. Power supply LKP-SP006.
Dimensions: With stand 941x616x211 mm, Without stand 941x569x85 mm.
TV weight: 13.4 kg.
Attention! The LTA400HM24 panel of the DNS V40DN54 LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.