TCLModel: 32E77NH20
Chassis / Version: 40-MT01TI-MAD2XG
Panel: LK315LZ54
Inverter (backlight): RDENC2287TPZA (IM3832A)
PWM Inverter: BD9777
MOSFET Inverter: RSS085, TPC8110
Power Supply (PSU): 40-1PL37C-PWE1XG
PWM Power: L6599 (16), L6563 (PFC 14pin), VIPER22A (Standby)
MOSFET Power: 2SK3568
MainBoard: 40-MT01TI-MAD2XG
IC MainBoard: MT8202, MT8293AE, S29AL016D70TFI02, ULB800057A
Tuner: TEDE9-2C2B
General repair guidelines for TV LCD
Possible manifestations of defects
- The TCL 32E77NH20 does not turn on at all. The control lights do not light or flash. The TV on the remote control and the control panel buttons do not respond.
With such manifestations, the 40-1PL37C-PWE1XG power module usually fails. Then we recommend that you measure its output voltages and, if they are absent, you should check the health of the power switches (2SK3568) and the rectifier diodes of the converters for possible short-circuit.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in emergency short circuit mode without output voltages, and during short circuit in the elements of the primary circuit, the mains fuse and, less often, the current sensor at the source of the key are most often cut off.
A breakdown of power switches (MosFet) in pulsed sources is sometimes caused by malfunctions of other circuit elements, for example, in circuits supplying a PWM controller, frequency-setting or damper ones, as well as in negative feedback (OOS) stabilization circuits. PWM controllers (PWM) L6599 (16), L6563 (PFC 14pin), VIPER22A (Standby), if they do not have visible damage to the case and open fault between the terminals, are usually checked by replacement.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
These manifestations can be triggered by a power supply module, or by inverter defects, as well as a distortion of the currents in the lamps due to their uneven wear. If all the electrolytic capacitors of the filter according to the inverter power supply are serviceable, you should make sure that the lamps are in good working condition, then you need to check the converter keys and the secondary windings of the transformers.
Sometimes, for diagnostic purposes, it is necessary to disable the inverter protection. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the 40-MT01TI-MAD2XG 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). When repairing an MB board, it is necessary to check its components MT8202, MT8293AE, S29AL016D70TFI02, ULB800057A. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
If the TV works normally from external devices, but does not tune into television channels, the TEDE9-2C2B tuner may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
The appearance of the MainBoard 40-MT01TI-MAD2XG is shown in the figure below:40-MT01TI-MAD2XG
Main features of the TCL 32E77NH20 device:
Installed matrix (LCD panel) LK315LZ54.
The RDENC2287TPZA inverter is used to power the backlight lamps, controlled by the BD9777 PWM controller. As power elements of the inverter, keys of the type RSS085, TPC8110 are used.
The necessary supply voltages for all nodes of the TCL 32E77NH20 TV are generated by the 40-1PL37C-PWE1XG power supply module or its analogs using L6599 (16), L6563 (PFC 14pin), VIPER22A (Standby) microcircuits and 2SK3568 power switches.
MainBoard - the main board (motherboard) is a 40-MT01TI-MAD2XG module, using chips MT8202, MT8293AE, S29AL016D70TFI02, ULB800057A and others.
The TEDE9-2C2B tuner provides TV reception and channel tuning.