Technical description and composition of the DEXP F42B7000ED TV, panel type and applicable modules. The composition of the modules.DEXP LED
Model: F42B7000ED
Chassis / Version: TP.S512.PB83
Panel: CX420DLEDM
LED backlight: CX42D10-ZC21FG-03
LED driver (backlight): integrated into PSU
PWM LED driver: SN510P
MOSFET LED driver: AOD4454
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: TP.S512.PB83
IC MainBoard: CPU: S2T512, SPI Flash: GD25Q64, RT9108NB
Tuner: R840
Technical Specifications F42B7000ED
DEXP F42B7000ED
General repair guidelines for TV LCD LED
Possible malfunctions
- The DEXP F42B7000ED TV does not turn on at all. There is no reaction to the remote control and control buttons from the front panel. Indicator lights do not light or flash.
First of all, in such cases, you should verify the operability of the common switching power supply (IIP) - AC / DC voltage converter of the mains voltage. All source elements in this TV model are located on the MainBoard TP.S512.PB83 main board. It is then necessary to measure its output voltages and, if they are absent, it is necessary to check the power switches and rectifier diodes of the converters for a short-circuit probability.
In case of breakdowns in the secondary circuits of the converter, it can usually fail in short circuit mode, and in case of a short circuit in the power elements of the primary circuit, the mains fuse or current sensor at the source of the key most often 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) PWM SOT23-6, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- 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 some of these cases, the malfunction is caused by a lack of backlighting on the 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 health in the LED circuit, it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED individually with a simple Chinese multimeter (powered by 9 volts) in the P-N-junction test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. A zener diode PN junction indirectly indicates a LED-a
- 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 TP.S512.PB83 motherboard should begin by checking the stabilizers and power converters needed to power the microcircuits and matrix. If necessary, update or replace the software (software). Sometimes it is necessary to check or replace (if necessary) the elements of the MainBoard - CPU: S2T512, SPI Flash: GD25Q64, RT9108NB. In cases where the BGA processor is used, its malfunction is usually detected by local heating.
If there is no reception of television channels, but the TV is working properly from external devices, first of all you need to check the voltage of the R840 tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
For F42B7000ED TV owners, we recommend that you contact qualified personnel with the necessary work experience for repairs! Self-repair attempts without the appropriate knowledge and skills can lead to irreversible negative consequences!
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> MainBoard TP.S512.PB83
FIRMWARE FOR SPI FLASH -----------> DEXP F42B7000ED, Main: TP.S512.PB83, Panel: CX420DLEDM
The appearance of MainBoard TP.S512.PB83 is shown in the figure below:TP.S512.PB83
TP.S512.PB83 can be used in TVs:
AKAI LEA-39V51P (Panel LC390TA2A 902-P05-390H ), DEXP 40A7000 (Panel C400F13-E2-C), DEXP F39B7100E (Panel T390HVN04.0 CX390DLEDM), DEXP H32B7000C (Panel T320XVN02.9 C320X14-E2-A), DEXP F42B7000ED (Panel CX420DLEDM), DEXP F32C7000B (Panel BOEI320WU1), DEXP F32C7100B/W F32C7100 (Panel BOEI320WU1), DEXP 32A7000 (Panel BOEI320WU1), DEXP 42A7000 (Panel CX420DLEDM), DEXP F32B7000B (Panel BOEI320WU1), DEXP H39D7000E (Panel CX390DLEDM), DEXP F40B7000C (Panel C400F13-E2-C), DEXP H32B3200CD (Panel HV320WX2-201), HAIER LE28F6000T (Panel A275HD1A01-2 / LVW280CSDO E2 V2), HAIER LE32F6000T (Panel ST3151A05-8 LVW320CSDX E13 V2), MYSTERY MTV-4025LT2 (Panel CX400DLEDM), SHIVAKI STV-32LED13 (Panel SV320SHD PDL320TU2A X41), SHIVAKI STV-42LED16 (Panel V420HJ-P01), SHIVAKI STV-32LED14 (Panel CX315DLEDM AJ32TO3), SHIVAKI STV-40LED13W (Panel V400HJ6PE1-C2), SHIVAKI STV-32LED15 (Panel HV320WHB-N80), SUPRA STV-LC32T440WL (Panel C320X14-E13-H), SUPRA STV-LC32T900WL (Panel LC320TU3A), SUPRA STV-LC40T900FL (Panel 1080p Full HD 1920x1080), THOMSON T32D15DH-01B (Panel LVW320CSDX E13 V30), THOMSON T28D15DH-01B (Panel LVW280CSDE E3 V5), THOMSON T32D16DH-01W T32D16DH (Panel LVW320CSDX E19 V28), THOMSON T43D16SF-01B T43D16SF (Panel LVF430LGDO E2 V18).
Main features of the DEXP F42B7000ED device:
Installed matrix (LED-panel) CX420DLEDM.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the SN510P PWM controller. As power elements of the LED driver, keys of the AOD4454 type are used.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using PWM SOT23-6 microcircuits.
MainBoard - the main board (motherboard) is a TP.S512.PB83 module, using CPU chips: S2T512, SPI Flash: GD25Q64, RT9108NB and others.
The R840 tuner provides TV reception and channel tuning.
DEXP F42B7000ED TV with a CX420DLEDM LCD, 42 "(107 cm) diagonal size in 16: 9 format. The required screen brightness of 250 cd / m² is provided by LED backlighting. Contrast - the ratio of maximum brightness to minimum is 3500: 1. In LCD -panels use direct LED backlighting with direct LEDs - Direct LED.The TV features include viewing programs and movies in high quality HD at a resolution of 1920x1080 pixels in a graphic resolution of 1080p (Full HD) standard. Input high-frequency or video drove decoded into analog PAL, SECAM system, NTSC Image processing and the formation of the digital signal is in 480i standards, 480p, 576i, 576p, 720p, 1080i, 1080p Supported multimedia file formats:.. MP3, MPEG4, JPEG.
The power of the acoustic system of sound 20 W (2x10 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, audio x2, VGA, HDMI x3, 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, 1280x1024, 1360x768, 1920x1080. A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Overall dimensions: without stand 973x568x88 mm.
The mass of the TV: without stand: 11.5 kg.
Attention! The CX420DLEDM panel of a DEXP F42B7000ED LED TV is an expensive and unreliable element.
Avoid any impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also unsafe to get liquid on the screen. Sometimes one drop is enough if it flows down the glass onto the cables so that the TV becomes unrepairable.