TELEFUNKEN LEDModel: TF-LED24S48T2
Chassis / Version: CV512L-U24
Panel: CX236DLEDM
LED backlight: Direct LED 38V 300mA CX236M01
LED driver (backlight): integrated in MainBoard
PWM LED driver: BIT3367A
MOSFET LED driver: MMBT3904
Power supply (PSU): integrated into the MainBoard
PWM power: LD5535
MOSFET power: 70R900P
Main board: CV512L-U24 // CV512L-Q24
MainBoard IC: CPU: S2T512, Flash SPI: 25Q64V, Audio: RDA3118E28
Tuner: CDT-9NT372-RD60
TELEFUNKEN TF-LED24S48T2
General Repair Instructions for LCD LCD TVs
Possible manifestations of faults:
- The TELEFUNKEN TF-LED24S48T2 television does not switch on, does not respond to the buttons on the remote control and the control panel, the indicators do not light up and do not flash.
First of all, in this case, you need to make sure that the common switching power supply (IIP) is the AC / DC voltage converter of the mains voltage. All of the source components for this TV model are located on the MainBoard CV512L-U24 main board. It is necessary to measure the output voltages in its secondary circuits and, if they are completely absent, to check the operating status of the power switches (70R900P) and the rectifying diodes to detect any possible failure (short circuit) .
In the event of faults in the secondary circuits, the converter can operate in short-circuit mode, and during a short-circuit in the elements of the primary circuit, the fuse generally breaks.
Failures of the Mos-Fet keys used in pulsed sources are often caused by malfunctions of other elements, for example in the power supply circuit of a PWM controller, in circuits with frequency or damping adjustment, as well than in negative stabilization return. PWM LD5535 circuits are generally checked by replacing them with new ones or by working obviously.
- 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.
Often in such cases there is no LED backlight. This may be due to a break in the LED circuit or a problem with stabilizing their power supply.
It is impossible to detect a break in the LED line without dismantling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a power source is suitable for such purposes. You can open the panel and check each indicator separately. Typically, Chinese multimeters will light a single 3-volt LED if you connect the probes in the direct direction (red probe at the anode, black at the cathode). In the case of two 6-volt LEDs, the PN junction of its emergency zener diode can be used as a health indicator. In the event of a malfunction of the LED, its Zener diode will either be cut or broken in short circuit.
Attention TV owners! Self-repair attempts by TELEFUNKEN TF-LED24S48T2 are not recommended by the manufacturer and can lead to serious negative consequences!- The front panel indicator flashes, the television does not switch on in operating mode, it does not respond to the remote control.
Service manual / schematic diagram -----------> Main CV512L-U24.
FIRMWARE SPI FLASH -------------> TELEFUNKEN TF-LED24S48T2, Main: CV512L-U24, Panel: CX236DLEDM.
FIRMWARE SPI FLASH -------------> TELEFUNKEN TF-LED24S48T2, Main: CV512L-Q24, Panel: CX236DLEDM.
Repairing or diagnosing the CV512L-U24 motherboard should start with checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). Complex MB repair (SSB) is only possible under the conditions of a service center with the necessary equipment. Checking or replacing the elements of the CPU: S2T512, SPI Flash: 25Q64V, Audio: RDA3118E28 requires the training and professional skills necessary to repair the modules at the component level. Heating can sometimes diagnose problems related to the use of BGA brazing technologies.
Before replacing the tuner CDT-9NT372-RD60, if there is no agreement for 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.
The appearance of the MainBoard CV512L-U24 is shown in the figure below:
CV512L-U24
Main features of the TELEFUNKEN TF-LED24S48T2 device:
Installed matrix (LED-panel) CX236DLEDM.
To power the backlight LEDs, a converter is used, combined with the main board CV512L-U24, controlled by the BIT3367A PWM controller. As power elements of the LED driver, keys of the type MMBT3904 are used.
The power module is combined with the MainBoard and is made according to the scheme of a flyback AC / DC voltage converter using LD5535 microcircuits and power switches of the type 70R900P.
MainBoard - the main board (motherboard) is a CV512L-U24 module, using CPU chips: S2T512, SPI Flash: 25Q64V, Audio: RDA3118E28 and others.
The tuner CDT-9NT372-RD60 provides the reception of television programs and tuning to channels.
