TELEFUNKEN LEDModel: TF-LED28S22
Chassis / Version: JUC7.820.00081373
Panel: M280X13-E1-H
LED backlight: SVJ280A01_REV3_5LED_130402
T-CON: MT3151A05-3-XC-1
LED driver (backlight): integrated in the PSU
PWM LED driver: OB3350CP
LED MOSFET driver: AODD4454
Power supply (PSU): integrated into the MainBoard
PWM power: NCP1251
MOSFET power: MDF7N65B
Main board: JUC7.820.00081373 LS0D
MainBoard IC: SPI Flash: EN25Q32
Tuner: R620D
Control: IR: JUC7.820.00081814
TELEFUNKEN TF-LED28S22
General Repair Instructions for LCD LCD TVs
Possible manifestations of faults
- The TELEFUNKEN TF-LED28S22 television does not switch on, does not respond to the remote control and the buttons on the control panel, the LEDs 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 main board JUC7.820.00081373. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches (MDF7N65B) and the rectifying diodes for a possible partial or complete failure.
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.
Mos-Fet switches, used in switch mode power supplies, sometimes fail due to a malfunction of any other element that could put it out of service in key mode or create an excess of the maximum admissible parameters of the switch. These can be elements supplying the PWM controller, frequency adjustment or damping circuits, or negative feedback elements in the stabilization circuit. The PWM NCP1251 controllers, in the absence of visible damage or open faults between the terminals, are checked by replacing them with new ones, or else in operation.
- There is no picture, there is sound, it responds to the remote control. Or, the image may appear for one second when it is turned on and immediately disappear.
The most likely in these cases is a malfunction of the LED backlight. Most of the time, the reason is the failure of the LEDs or insufficient contact in the connectors of the modules. Less often, the LED driver may not function properly.
When diagnosing, it is necessary to take into account that it is impossible to control the opening in the circuit of the LED lines without dismantling the panels with a tester or a multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required and, ideally, a current source. By opening the panel, each LED can be checked separately. Typically, Chinese multimeters will light a single 3-volt LED if you connect probes in the forward direction. 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.
- The television does not switch on, does not respond to the remote control. The LED flashes or signals standby mode.
Repair or diagnosis of the JUC7.820.00081373 motherboard should begin by checking the stabilizers and power converters needed to power the chips and the array. If necessary, you must update or replace the software (software). Often, the MB (SSB) card must be replaced in the event of complex malfunctions that are difficult to detect. When trying to repair, you need to check its parts - SPI Flash: EN25Q32 and replace the failed chips with new ones. Some malfunctions may be due to the use of BGA soldering technologies in the modern motherboard. Typically, such faults are detected by local heating of the chip.
Before changing the R620D tuner, if it is not possible to tune in the TV channels, you must make sure that supply voltages must be measured at the corresponding terminals of the tuner and that the software is correct. The pulses of the data exchange from the tuner to the processor can be monitored by an oscilloscope
It must be remembered! Any attempt to independently repair the TELEFUNKEN TF-LED28S22 TV, in the absence of the necessary qualifications and experience, is formally discouraged and has negative consequences which may go as far as not fully repairing the device!
FIRMWARE SPI FLASH ----------> TELEFUNKEN TF-LED28S22, Main: JUC7.820.00081373, Panel: M280X13-E1-H
The figure below illustrates the appearance of the MainBoard JUC7.820.00081373:JUC7.820.00081373
JUC7.820.00081373 can be used in televisions:
AKAI LEA-32C25M (Panel M320X13-E1-H), ERISSON 32LEC2300 (Panel M320X13-E1-L), FUSION FLTV-28L32B (Panel M280X13-E1-H).
Main features of the TELEFUNKEN TF-LED28S22 device:
Installed matrix (LED-panel) M280X13-E1-H.
The matrix control uses the Timing Controller (T-CON) MT3151A05-3-XC-1.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the OB3350CP PWM controller. As power elements of the LED driver, keys of the type AODD4454 are used.
The power supply module is combined with the MainBoard and is designed according to a flyback AC / DC voltage converter using NCP1251 microcircuits and power switches of the MDF7N65B type.
MainBoard - the main board (motherboard) is a JUC7.820.00081373 module, using SPI Flash chips: EN25Q32 and others.
The R620D tuner provides TV reception and channel tuning.
