Technical description and composition of the TOSHIBA 48L3663DG TV, type of panel and applicable modules. The composition of the modules.TOSHIBA LED
Model: 48L3663DG
Chassis / Version: 17MB110P
Panel: LSC480HN08-802
T-CON: 15Y_L48GF11BMB7S4LV0.6
LED driver (backlight): integrated into PSU
PWM LED driver: MP3394
MOSFET LED driver: FQD7N10L
Power Supply (PSU): 17IPS12
PWM Power: FAN6300
MOSFET Power: FQPF9N50C
MainBoard: 17MB110P
IC MainBoard: M88RS6000, SI2151, 25L1606
Specifications 48L3663DG
TOSHIBA 48L3663DG
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The TOSHIBA 48L3663DG TV does not turn on and does not show any signs of operability at all. There is no reaction to the remote control and control buttons from the front panel.
Typically, with such manifestations, the defect is caused by faulty elements in the 17IPS12 main power module. It is necessary to measure its output supply voltage, and in case of their absence, check the serviceability of the power switches (FQPF9N50C) of the converters and rectifier diodes for the probability of breakdown in PN semiconductor junctions.
In case of breakdowns of semiconductors in the secondary circuits, the converter can usually work abnormally in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse often breaks.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damping circuits, or negative feedback elements in the stabilization circuit. FAN6300 PWM controllers, in the absence of visible damage or explicit short-circuit between the terminals, are checked by replacing with new ones, or obviously working.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
Usually in such cases, a malfunction is detected in the backlight nodes of the LED panel. The reason can be both in the power 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 17MB110P 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). In cases of attempts to repair the MB board (SSB), it is necessary to check the health of its elements - M88RS6000, SI2151 which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its conclusions with the board (it is diagnosed by heating).
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.
TV LED IC MP3394/MPS3394S LED Driver Diagnostics Throubleshooting
The earlier MP3394 was replaced by MPS3394S, which is an upgraded version of the same IC, and found in the 17IPS20 power supply board. It is the main heart of the backlighting LED drive and the failure of this IC can cause the TV not to start. This is a voltage step-up IC that takes 5-V to 28-V at its input pin 15 (Vin) and raises it to drive four independent strings of LEDs. It also performs other functions such as voltage regulation between the LED strings, and provides a dimming facility using pulse-width modulation (PWM). An important aspect of this IC is that it has built-in open and short LED protection circuitry. It is also able to sense the current and voltage of the LED matrix load and determine abnormal conditions. That means that if all the LEDs in the matrix go open or short, it will prevent the television from switching ON.
The IC has internal control logic that produces the GATE signal to drive an external MOSFET transistor. This is the transistor that is switched against an inductor to step-up the voltage, and the gate signal is produced only when the internal control logic detects normal conditions. It is able to determine normal/abnormal conditions through internal comparators, and one such is the LED Over-Voltage Protection (LED OVP) comparator that provides Short String Protection (SSP).
When the TV is switched ON, this IC is enabled through pin 2, by a voltage greater than 1.8-V. It first checks the circuit configuration, and then checks the over-voltage protection signal at (pin 12) to determine if the rectifier diode is open and whether the booster MOSFET (driven by the GATE signal) is short to ground. If the OVP voltage at pin 12 is lower than 70-mV (may be different for other board versions), then it disables itself and the TV will not start.
On the 17IPS20 board, the GATE signal is known as GATE_LED, which drives a bi-polar junction transistor (BJT) Q500 (BC858B). This transistor then drives Q502/Q503 MOSFET booster group of transistors to step-up the voltage (shown in the following pages of this article). In this circuit configuration the inductance coils are L500 and L501. The high voltage produced then goes into a group of rectifier diodes D503 and D504 producing a positive DC voltage for the LEDs. The over voltage protection signal is known as OVP_LED. Whilst all the LED strings take their power from this positive voltage source, they all have separate independent drain pins through the MPS3394S controller IC.
There are also other parameters to consider such as Under-Voltage Lock-Out (UVLO), which is determined by measuring the rising-edge of Vin. This parameter has to be between 3.5-V and 4.4-V, with 3.9-V being the typical value. It is a very clever IC as it can also detect open and short LED strings in the backlight array.
Although this diagnostic cannot tell you the condition of each individual diode, it can indicate the condition of each string of diodes in the backlight matrix. The MPS3394S IC (SOIC16 package) drives four separate strings of LEDs through dedicated open drain output pins. LED string 1 is driven by pin 11, LED string 2 by pin 10, LED string 3 by pin 9, and LED string 4 by pin 8. It also monitors the voltages at these pins so that if there was a shorted LED in one of the strings then it would disconnect that string. If the voltage at any of these pins is greater than 6.1-V, then this condition triggers the short circuit protection mechanism for disconnecting the string at that pin. It is also possible to determine an open string, and in this case, this condition is detected when the pin voltage is lower than 196-mV.
Interestingly, this IC is designed such that it will always try to light at least one string if it is working. The only time when the step-up converter shuts-down completely is if all the strings were either open, or short. Therefore, before you rush off to eBay to buy a new chip, measure the voltages at these pins to make sure that the diodes are not faulty. Otherwise, you will end up wasting a lot of time and money!
The appearance of the MainBoard 17MB110P is shown in the figure below:17MB110P
Main features of the TOSHIBA 48L3663DG device:
Installed matrix (LED panel) LSC480HN08-802.
The matrix control uses the Timing Controller (T-CON) 15Y_L48GF11BMB7S4LV0.6.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the MP3394 PWM controller. As power elements of the LED driver, keys of the FQD7N10L type are used.
The necessary supply voltages for all nodes of the TOSHIBA 48L3663DG TV are generated by the 17IPS12 power supply module or its analogs using FAN6300 microcircuits and power switches of the FQPF9N50C type.
MainBoard - the main board (motherboard) is a 17MB110P module, using microchips M88RS6000, SI2151, 25L1606 and others.
To reduce the backlight current in LED drivers with the MP3394S (MP3394) controller, increase the resistance of the resistor from pin 6 (ISET) to the chassis. The maximum current in each channel (in milliamperes) for the Rset resistor (in kilo-ohms) is determined from the ratio 790 * 1.23V / (Rset + 0.4).
Brand: TOSHIBA, Model: 48L3663DG.
Briefly from the TV: LCD, LED backlight, 48 ", 1920x1080, 1080p Full HD, DVR, there is a satellite tuner, sound: 16W, HDMI: 3, Internet access, Wi-Fi, Smart TV.
The composition uses MainBoard 17MB110P and LCD-panel LSC480HN08-802.
Power Supply Unit (PSU) 17IPS12 Power Supply.
Technical description
TOSHIBA 48L3663DG LED TV with LSC480HN08-802 LCD display, 48 "(122 cm) diagonal size in 16: 9 format. The LCD panel uses backlighting from Direct LEDs. The design and technical capabilities of the TV include watching programs and movies in high quality HD at a resolution of 1920x1080 pixels in the graphic decomposition of the standard 1080p (Full HD).
The 48L3663DG is equipped with SMART software, integrated applications and the ability to work on the Internet. Connecting to the Internet can be done via Wi-Fi. Supported media file formats: HEVC (H.265).
The power of the sound system 16 W (2x8 W) provide two speakers. It uses a NICAM stereo signal processing system and Sound Surround.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, VGA, HDMI x3, USB x2, Ethernet (RJ-45), Wi-Fi, Miracast. An output for connecting headphones is provided.
The digital tuner is capable of receiving television channels in the standards DVB-T MPEG4, DVB-C, DVB-T2, DVB-S2.
Attention! The LSC480HN08-802 panel of the TOSHIBA 48L3663DG 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.
