Technical description and composition of the HARPER 42F0540 TV, panel type and modules used. The composition of the modules.HARPER LED
Model: 42F0540
Chassis / Version: LAD.MV59S.G
Panel: T420HVN07.1
LED driver (backlight): integrated into MainBoard
Power Supply (PSU): integrated into MainBoard
MainBoard: LAD.MV59S.G
IC MainBoard: CPU: TSUMV59XUS, SPI FLASH: MX25L32
Specifications 42F0540
HARPER 42F0540
General recommendations for TV LCD LED repair
Possible manifestations of defects
- TV HARPER 42F0540 does not turn on and does not show any signs of operability at all. No response to the remote control and front panel control buttons.
In such cases, the common power source is often faulty - the AC / DC converter of the mains voltage, which is combined with the elements of the LAD.MV59S.G main board. Then you should measure its output voltages and, in case of their complete or partial absence, it is necessary to check the serviceability of the power switches and rectifier diodes of the converters for a possible short circuit.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in an emergency mode of short circuit without output voltages, and with a short circuit in the elements of the primary circuit, the mains fuse most often breaks off immediately and, less often, the current sensor in the source of the key.
Mos-Fet power switches used in switching power supplies sometimes fail due to a malfunction of any other elements that can disable it in the key mode, or create an excess of the maximum permissible key parameters. These can be elements supplying a PWM regulator, frequency setting or damper circuits, or elements of negative feedback in the stabilization circuit. PWM controllers, in the absence of visible damage or outright short circuits between the terminals, are checked by replacing them with new ones, or knowingly working properly.
- There is no image, there is sound, it reacts to the remote control. Or, immediately after switching on for a second, the image may appear and immediately disappear.
A malfunction is usually in these cases most likely in the backlight units of the display matrix. Usually the cause of the malfunction is in the breakage of the LEDs, or in the connectors of the LED strips, but sometimes the LED driver is also faulty.
It is impossible to check the LED bars for a break without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters tend to light a single 3V LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as an indicator of serviceability. In faulty LEDs, the zener diode will either be cut off, or pierced in the K / Z.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals the standby mode.
Repair or diagnostics of the LAD.MV59S.G motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - CPU: TSUMV59XUS, SPI FLASH: MX25L32 with new or known good ones. In cases where BGA technologies are used, defects are usually localized by heating.
Attention to TV owners! Attempts to repair HARPER 42F0540 yourself are not recommended by the manufacturer and can lead to serious negative consequences!
DOWNLOAD FIRMWARE FOR SPI FLASH -----------> HARPER 42F0540, Main: LAD.MV59S.G, Panel: T420HVN07.1
The appearance of the MainBoard LAD.MV59S.G is shown in the figure below:LAD.MV59S.G
Main features of the HARPER 42F0540 device:
Installed matrix (LED panel) T420HVN07.1.
A converter combined with the main board LAD.MV59S.G is used to power the backlight LEDs.
The power module is combined with the MainBoard and is made according to the AC / DC flyback converter circuit.
MainBoard - the main board (motherboard) is a LAD.MV59S.G module, using CPU chips: TSUMV59XUS, SPI FLASH: MX25L32 and others.
Additional technical information about the panel:
Brand: AUO
Model: T420HVN07.1 CELL
Type: a-Si TFT-LCD, CELL
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: AMVA3, Normally Black, Transmissive
Active Area: 930.24x523.26 mm
Surface: Antiglare (Haze 2%), Hard coating (3H)
Transmissivity: 5.6% (with Polarizer)
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit)
Response Time: 6.5 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V
HARPER 42F0540 TV with LCD T420HVN07.1, 42 "(107 cm) 16: 9 diagonal. The LED panel of this TV implements Edge LED backlighting. The design and technical capabilities of the TV provide viewing of programs and films in high quality HD at a resolution of 1920x1080 pixels in graphic resolution according to the standard 1080p (Full HD) .Input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal formation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p Supported media file formats: MP3, WMA, MPEG4, DivX, MKV, JPEG.
Speaker power 14 W (2x7 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), HDMI x2, USB. A headphone output is provided. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector on the TV case is used, this interface supports resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080.
Overall dimensions: 970x620x210 mm.
TV weight: 11 kg.
Attention! HARPER 42F0540 LED TV panel T420HVN07.1 is an expensive and unreliable element.
Do not allow any impacts on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV non-repairable.
