Technical description and composition of the ERISSON 24LT12 TV, type of panel and applicable modules. The composition of the modules.ERISSON
Model: 24LT12
Chassis / Version: MT8223
Panel: V236H1-L01 Rev. C3
Inverter (backlight): integrated into PSU
Power Supply (PSU): SHP2404A-101 Rev: 7.0
PWM Power: LD7575
MOSFET Power: 2SK3115
MainBoard: 40-MT8223-MAH2XG
IC MainBoard: CPU: MT8223LFHU, SPI Flash W25Q16BVSIG
Tuner: TDQ-3EPD
Specifications 24LT12
ERISSON 24LT12
General recommendations for repairing TV LCD
Possible malfunctions
- The ERISSON 24LT12 TV does not turn on and does not show any signs of turning on, does not respond to the control buttons or to the remote control.
In some of these cases, the main switching power supply, the SHP2404A-101 module, is faulty. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, check the serviceability of power switches (2SK3115) and rectifier diodes for possible breakdown (short circuit).
In case of diode breakdowns in the secondary circuits, the converter can operate in emergency short-circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key 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. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM) LD7575, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- 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 module, or by defects in the inverter, as well as a distortion of the currents in the lamps due to their uneven wear. After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, it is necessary to ring in its converter power keys for breakdown and secondary windings of transformers for an open.
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 TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the 40-MT8223-MAH2XG 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). Often, the MB (SSB) card must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - CPU: MT8223LFHU, SPI Flash W25Q16BVSIG and replace failed chips with new ones. Some malfunctions may be due to the use of BGA soldering technologies in modern Main Board technologies. Typically, such defects are detected by local heating of the chip.
If the TV works normally from external devices, but does not tune into television channels, the TDQ-3EPD tuner may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. 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.
Attention! For users and owners of 24LT12 TVs who do not have the appropriate qualifications, knowledge and experience, we categorically do not recommend attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.
Repair MainBoard
The appearance of the MainBoard 40-MT8223-MAH2XG is shown in the figure below:
40-MT8223-MAH2XG
40-MT8223-MAH2XG can be used in TVs:
ERISSON 32LT12 (Panel LTA320AP07), ERISSON 24LT12 (Panel V236H1-L01 Rev. C3).
The appearance of the power supply
Main features of the ERISSON 24LT12 device:
Installed matrix (LCD panel) V236H1-L01 Rev. C3.
To power the backlight, a converter is used, combined with a power supply.
The necessary supply voltages for all nodes of the TV ERISSON 24LT12 are generated by the SHP2404A-101 power supply module or its analogs using LD7575 microcircuits and 2SK3115 power switches.
MainBoard - the main board (motherboard) is a 40-MT8223-MAH2XG module using CPU chips: MT8223LFHU, SPI Flash W25Q16BVSIG and others.
The TDQ-3EPD tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: CMO
Model: V236H1-L01
Type: a-Si TFT-LCD, Panel
Diagonal size: 23 inch
Resolution: 1920x1080, FHD
Display Mode: TN, Normally White, Transmissive
Active Area: 521.28x293.22 mm
Surface: Antiglare (Haze 25%), Hard coating (3H)
Brightness: 300 cd / m²
Contrast Ratio: 800: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 72%
Response Time: 1.5 / 3.5 (Tr / Td)
Frequency: 60Hz
Lamp Type: 2 pcs CCFL Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 30 pins
Voltage: 5.0V
Brand: ERISSON, Model: 24LT12.
Shortly from the TV: LCD, 1080p Full HD, diagonal 24 "(61 cm), there is HDMI, there is USB.
The composition uses MainBoard 40-MT8223-MAH2XG and LCD panel (matrix) V236H1-L01 Rev. C3.
Power Supply Unit (PSU) SHP2404A-101 Rev: 7.0 Power Supply.
ERISSON 24LT12 TV with V236H1-L01 LCD, 24 "(61 cm) diagonal size of 16: 9 format. 300 cd / m² screen brightness is provided by CCFL (EEFL) fluorescent lamps. The design and technical capabilities of the TV include watching programs and movies in high quality HD at a resolution of 1920x1080 pixels in graphic decomposition according to the standard 1080p (Full HD). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i , 576p, 720p, 1080i, 1080p. Supported media file formats: MP3, JPEG.
The power of the sound system 6 W (2x3 W) provide two speakers. The audio processing system NICAM STEREO is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV x2, audio x3, S-Video, component, VGA, HDMI, USB. An output for connecting headphones is provided. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector is used on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768.
Overall dimensions: With a support of 605x465x210 mm, Without a support of 605x405x93 mm.
Attention! The V236H1-L01 Rev. C3 panel of the ERISSON 24LT12 LCD TV is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!