Technical description and composition of the PHILIPS 32PHT4001 TV, type of panel and applicable modules. The composition of the modules.PHILIPS LED
Model: 32PHT4001 / 60
Chassis / Version: KTS16.1E LA
Panel: K320WD92
LED backlight: 4708-K320WD-A4213K01
T-CON: HV320WHB-N80
LED driver (backlight): integrated into MainBoard
PWM LED driver: MP3394S
MOSFET LED driver: AOD256
Power Supply (PSU): integrated into MainBoard
PWM Power: OB5269CP
MOSFET Power: AOTF10N65
MainBoard: MSD3463-T8C1
IC MainBoard: MSD3463-T8C, MX25L6406, TPA3110D2
Tuner: NoName
Specifications 32PHT4001
PHILIPS 32PHT4001
General repair guidelines for TV LCD LED
Possible manifestations of defects
- PHILIPS 32PHT4001 does not turn on and does not show any signs of performance at all. Does not blink indicators and does not respond to control buttons.
In such cases, the main power source, the AC / DC voltage converter, which is combined with the MainBoard MSD3463-T8C1 board, may turn out to be faulty. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, check the serviceability of the power switches (AOTF10N65) and rectifier diodes for possible breakdown (short circuit).
In the event of a breakdown 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 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. PWM controllers OB5269CP, in the absence of visible damage or explicit short-circuit between the terminals, are checked by replacing with new, or obviously working.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
A malfunction is usually most likely in these cases at the backlight nodes of the display matrix. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
To detect a break in the LED lines without disassembling the panel, a current source is required. It is impossible to open transitions connected in series with a simple multimeter; voltage of several tens of volts is necessary.
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the motherboard MSD3463-T8C1 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 serviceability of its elements - MSD3463-T8C, MX25L6406, TPA3110D2 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).
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 NoName tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Once again, I remind users! Attempts to independently repair a PHILIPS 32PHT4001 TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
FIRMWARE FOR SPI FLASH -------> PHILIPS 32PHT4001/60, Main: MSD3463-T8C1, Panel: K320WD92
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)
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 MSD3463-T8C1 is shown in the figure below:MSD3463-T8C1
MSD3463-T8C1 can be used in TVs:
PHILIPS 32PHT4001/60 (Panel K320WD92), PHILIPS 43PFT4001/60 (Panel K430WD9), TELEFUNKEN TF-LED39S35T2 (Panel K390WD5 K390WD5UB280H200), TELEFUNKEN TF-LED32S35T2 (Panel K320WD5).
Key Features of PHILIPS 32PHT4001:
Installed matrix (LED-panel) K320WD92.
The matrix control uses the Timing Controller (T-CON) HV320WHB-N80.
To power the backlight LEDs, a converter is used, combined with the main board MSD3463-T8C1, controlled by the MP3394S PWM controller. As the power elements of the LED driver, keys of the AOD256 type are used.
The power module is combined with the MainBoard and is made according to the scheme of a flyback AC / DC voltage converter using OB5269CP microcircuits and power switches of the AOTF10N65 type.
MainBoard - the main board (motherboard) is an MSD3463-T8C1 module, using microchips MSD3463-T8C, MX25L6406, TPA3110D2 and others.
The NoName tuner provides television reception and channel tuning.