TELEFUNKEN LEDModel: TF-LED28S18
Chassis / Version: MS82MT
Panel: TH280-L03
LED backlight: TC280-F1004-YTJ-LA2
T-CON: ST3151A05-4-XC-3
LED driver (backlight): integrated in the PSU
PWM LED driver: OB3362RP
Power supply: 40-ES2820-PWE1XG
Main board: 40-MS82MT-MAB2HG
MainBoard IC: MST6M300ST, 24C32
Tuner: NoName
TELEFUNKEN TF-LED28S18
General Repair Instructions for LCD LCD TVs
Possible malfunctions
- The TELEFUNKEN TF-LED28S18 television does not switch on. There is no sign of operability. The front panel lights do not light up or blink, the TV does not respond to buttons on the remote control and control buttons.
With such manifestations, in some cases, the 40-ES2820-PWE1XG power module is defective. Then, we recommend that you measure its output voltages and, if they are not present, check the state of health of the current switches and rectifier diodes of the converters in order to detect any possible short circuit.
In the event of semiconductor failures in the secondary circuits of any converter, it can generally operate in emergency short-circuit mode without output voltages and during a short-circuit in the elements of the primary circuit, the fuse main and, less often, the current sensor at the source of the key.
Mos-Fet keys used in switch mode power supplies generally fail due to a malfunction of other elements likely to put it out of service in key mode or to cause an excess of current or maximum voltage. These can be circuits supplying the PWM controller, damping or frequency adjustment circuits, or negative feedback elements in the stabilization circuit. PWM controllers (PWM), in the absence of external damage and a short circuit between the terminals, are checked by replacing them with good ones.
- There is no picture, there is sound, there is a reaction to the remote control. Or immediately after turning it on for a second, the image may appear and disappear immediately.
Usually, in such cases, a malfunction is detected in the backlight nodes of the LED panel. This can be due to both the power supply of the LEDs, their operating state (failure or breakage) and the violation of the contact connections of the LED strips.
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 front panel indicator flashes, the television does not switch on in operating mode, it does not respond to the remote control.
Repairing or diagnosing the 40-MS82MT-MAB2HG 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). The repair and replacement of the MST6M300ST, 24C32 microcircuit card is carried out with the necessary equipment and the base of the corresponding element. Faults associated with the application of BGA processor welding technologies can be located by the heating method.
Before replacing the NoName tuner, if there is no agreement on the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to ensure that the tuner and the processor can exchange data via the I2C bus.
Again, we remind television users: you should not attempt to repair it yourself without the required knowledge, experience and qualifications! Entrust the repair to professionals sufficiently experienced in the repair of electronic equipment
