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, 17 December 2019

REPAIRING / SERVICING TV TELEFUNKEN TF-LED28S19

TELEFUNKEN LED
Model: TF-LED28S19
Chassis / Version: MS306DPS
Panel: LVW280CSOT
T-CON: MT3151A05-5-XC-5 ST2751A01-8
LED driver (backlight): integrated in MainBoard; OUT = 33V
Power supply (PSU): integrated into the MainBoard
PWM power: PWM SOT23-6
Main board: 40-MS306D-MAD2LG MS306DPS
IC MainBoard: SPI FLASH: W25Q32FVSIG
Tuner: XF-3SDT-H
TELEFUNKEN TF-LED28S19
General Repair Instructions for LCD LCD TVs

Possible manifestations of faults

- TELEFUNKEN TF-LED28S19 does not light up, the LEDs on the front panel do not light up and do not flash. The TV does not respond to the control buttons and the remote control.
Malfunction in such cases should be looked for in the elements of the power source - the network voltage converter (AC / DC), located on the main board MainBoard 40-MS306D-MAD2LG. It is necessary to measure the secondary output supply voltages and, if not, check the functionality of the power switches of the converters and the rectifier diodes to determine the probability of failure of the PN semiconductor junctions.
In the event of diode failures in the secondary circuits, the converter can operate in emergency short-circuit mode without output voltages and during a short-circuit in the power elements of the primary circuit, the network fuse and / or the current sensor at the source of the key usually breaks.
Failures of the Mos-Fet keys used in pulsed sources are often caused by malfunctions of other elements, such as power, frequency adjustment, register, etc., as well as by stabilization feedback elements negative. PWM PWM SOT23-6 can also cause the converter power switch to malfunction and is checked for replacement
.
- There is no picture, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn it on and immediately disappears.
The most likely in these cases is a malfunction of the LED backlight. This may be due to a break in the LED circuit or a problem with stabilizing their power supply.
When trying to identify a break in the LED lines, you should keep in mind that it is difficult to do so without dismantling the panel. For example, a power source is required to open PN junctions connected in series.

- The television does not enter operating mode, does not respond to the remote control. The indicator on the front panel is permanently on or blinking.

Repairing or diagnosing the 40-MS306D-MAD2LG motherboard should start by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). In some cases, to repair the MB (SSB) card, it may be necessary to replace the - 25Q32 chips with new or obviously good ones. In cases where BGA technologies are used, faults are generally located by the heating method.

If you suspect a malfunction of the XF-3SDT-H tuner, you should first check the accuracy of the software, as well as the presence of the necessary supply voltage levels and pulses of data exchange with the processor via the I2C bus to the corresponding terminals of the tuner.
It must be remembered! Any attempt to repair the TELEFUNKEN TF-LED28S19 independently, in the absence of the required qualifications and experience, is formally discouraged and has negative consequences which may go as far as not fully repairing the device!