Technical description and composition of the HAIER LE42Z300R3D TV, panel type and applicable modules. The composition of the modules.Haier LED
Model: LE42Z300R3D
Chassis / Version: 0171-2272-4142
Panel: LC420EUG RDF1 7R1
LED driver (backlight): integrated into PSU
Power Supply (PSU): DPS-141DP A
MainBoard: 0171-2272-4142
IC MainBoard: MT5308, 24C32
Tuner: HFT-8CH / V1.16R
Control: HTR-D3D
Appearance
HAIER LE42Z300R3D
General repair guidelines for TV LCD LED
Possible manifestations of defects
- Haier LE42Z300R3D TV does not turn on. There are no signs of operability. The indicators on the front panel do not shine and do not blink, and the remote control and control buttons do not respond.
With such manifestations, a malfunction is most likely to be detected in the DPS-141DP power module. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary first of all to check the power switches and rectifier diodes for a possible partial or complete breakdown.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during short circuit in the elements of the primary circuit, the mains fuse usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. It can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power switch may be PWM (PWM). It is checked only by replacement with a known good one.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and disappears.
In most cases, the malfunction is caused by the lack of a backlight display. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
To check the LED lines for breaks without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter, a voltage of the order of several tens of volts is required.
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the 0171-2272-4142 motherboard should begin by checking the stabilizers and power converters needed to power the microcircuit and matrix. If necessary, update or replace the software (software). When repairing an MB board, you need to check its components MT5308, 24C32. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the method of local heating of the chip.
If the TV works normally from external devices, but does not tune into television channels, the HFT-8CH / V1.16R 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.
Once again, remind users! Attempts to independently repair a Haier LE42Z300R3D TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> HAIER LE42Z300R3D
The appearance of MainBoard 0171-2272-4142 is shown in the figure below:0171-2272-4142
Key Features of HAIER LE42Z300R3D:
Installed matrix (LED-panel) LC420EUG RDF1 7R1.
To power the backlight LEDs, a converter is used, combined with a power supply.
The formation of the necessary supply voltages for all nodes of the HAIER LE42Z300R3D TV is carried out by the DPS-141DP power module, or its analogues.
MainBoard - the main board (motherboard) is a module 0171-2272-4142, using chips MT5308, 24C32 and others.
The HFT-8CH / V1.16R tuner provides television reception and channel tuning.
