Technical description and composition of the LG 24MT58VF-PZ TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 24MT58VF-PZ
Chassis / Version: LD60A
Panel: HM238EUN-SLMP1-41XX (V236BJ1-LE2 B REV.C8)
LED backlight: 238RL.L REV1.0 15452L
LED driver (backlight): integrated into MainBoard
PWM LED driver: MP3378E
Power Supply (PSU): Adapter 19V
MainBoard: EAX66873503 (1.2)
IC MainBoard: CPU: LGE6351, Audio: M28720, SPI FLASH: 25L8005, Eeprom: 4G25 (24C256)
Tuner: TDJA-G301D
Technical Specifications 24MT58VF-PZ
LG 24MT58VF-PZ
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 24MT58VF-PZ TV does not turn on, does not respond to the remote control and the control panel buttons, does not light up or blink indicators.
Most often, with such manifestations, the main adapter power module is found to be faulty.
The TV model under consideration is equipped with an external adapter 19V power supply, the repair of which is not always advisable, but opening it and eliminating the simplest typical defects typical of modern IIPs is usually not difficult for a qualified craftsman. It is necessary to measure its output voltages and, if they are absent, to check for short-circuit probabilities in the converters, power switches and rectifier diodes.
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 main fuse and, less often, the current sensor at the source of the key most often breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM microcircuits are usually checked by replacement with new ones, or obviously working.
- There is no image, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn on and immediately disappears.
In such cases, the most likely malfunction of the LED backlight elements. More often the reason for this is the breakdown of the LEDs, or poor contact in the connectors of the strips, less often the LED driver may be faulty.
When trying to detect a break in the LED lines, it should be taken into account that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the EAX66873503 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). If it is not possible to replace the MB (SSB) board, you need to check the health of its elements - CPU: LGE6351, Audio: M28720, SPI FLASH: 25L8005, Eeprom: 4G25 (24C256). Defective components should be replaced.
If a TDJA-G301D tuner is suspected of malfunction, first of all, it is necessary to verify the correctness of the software, as well as the presence of the necessary supply voltage levels and data exchange pulses with the processor via the I2C bus at the corresponding tuner terminals.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Entrust repair to professionals with sufficient experience in the field of repair of electronic equipment.
Service manual and schematic diagram LG 24MT58VF-PZ Chassis LD60A
To reduce the backlight current in LED drivers with the MP3378E PWM controller, it is necessary to proportionally increase the total resistance of the resistors from pin 3 (RISET) to the chassis. Calculation of current in milliamperes and resistance in kilo-ohms 977 / Rset for each channel. Parallel channels are summed. For example, for four parallel channels and a RISET 10 KOhm resistance, the total current will be 97.7 * 4 = 391 mA.
More details on this page
The appearance of the MainBoard EAX66873503 is shown in the figure below:EAX66873503
EAX66873503 can be used in TVs:
LG 22LH450V PZ (Panel HM215EUN-SLMP1 - 41XX), LG 24LH450U (Panel V236BJ1-LE2A), LG 28LH451U (Panel HC275EXN-ABVP1-41XX), LG 20MT48VF 20MT48VF-PZ (Panel 1366x768 720p HD).
Main features of the device LG 24MT58VF-PZ:
The matrix (LED panel) HM238EUN-SLMP1-41XX (V236BJ1-LE2 B REV.C8) is installed.
To power the backlight LEDs, a converter is used, combined with the main board EAX66873503, controlled by the MP3378E PWM controller.
To power all the internal components of the LG 24MT58VF-PZ TV, an external adapter 19V type source is used.
MainBoard - the main board (motherboard) is an EAX66873503 module using CPU chips: LGE6351, Audio: M28720, SPI FLASH: 25L8005, Eeprom: 4G25 (24C256) and others.
The TDJA-G301D tuner provides TV reception and channel tuning.