Wednesday, 29 January 2020

REPAIR / SERVICING TV PHILIPS 40PFL4528T

Technical description and composition of the PHILIPS 40PFL4528T TV, type of panel and applicable modules. The composition of the modules.
PHILIPS LED
Model: 40PFL4528T / 60
Chassis / Version: TPM10.1E LA
Panel: LTA400HF30
T-CON: 715G5787-P02-000-002S
LED driver (backlight): 715G5787-P02-000-002S
Power Supply (PSU): 715G5792-P03-000-002M
PWM Power: LD7591T (PFC), SSC1S311, PF8200S
MOSFET Power: K15A60
MainBoard: 715G5713-M0F-000-005K
IC MainBoard: CPU: MT5580MPOI, DRAM: NT5CB256M8GN, NAND: TC58NVG2S3ETA00, EEPROM: 24C128
Tuner: TDSY-G230D
Specifications 40PFL4528T
PHILIPS 40PFL4528T
General repair guidelines for TV LCD LED
In the absence of any signs of operability, when the PHILIPS 40PFL4528T does not turn on and does not signal anything with the control lights on the panel, there is a possibility of a malfunction of the power supply module 715G5792-P03-000-002M of the TV. First of all, it is necessary to replace the swollen capacitors of the rectifier filters, if any. If the mains fuse is broken in the power supply, in most cases a breakdown of the power key (s) K15A600, 11N70 is detected. which can be integrated with a PWM controller, or a separate field effect transistor can be used. The rectifier bridge diodes and the electrolytic capacitor of the mains rectifier filter should also be checked.
In most cases, key breakdowns in switching power supplies (SMPS) do not occur for no reason and you should look for other faulty circuit elements that could provoke a defect. This can be dried electrolytic capacitors in the primary circuit, and faulty damper elements, as well as dangling resistors or punched semiconductor elements in the stabilization circuits. Possible defective PWM NR111D chip from the manufacturer.
If the PHILIPS 40PFL4528T has no image, there is sound and the channels are switched, there is a possibility of a malfunction in the circuit of the backlight LEDs of the LTA400HF30 panel, or their power converter - LED driver. Sometimes, when turned on, the image appears and immediately disappears. In such cases, it is necessary to check the electrolytic capacitors of the power filter of the backlight unit.
Often in the absence of backlighting, disassembling the panel is required. It is necessary to check the serviceability of the transitions of the LEDs, as well as the reliability of the contact connections in the rulers and connectors.
It is impossible to check the LED line for breaks 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, as a rule, light up a single 3-volt 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 a health indicator. In faulty LEDs, the zener diode will either be cut off or broken into short-circuit.
Repair of the motherboard 715G5713-M0F-000-005K must begin with the diagnosis and verification of all linear stabilizers and power converters of its microcircuits. Sometimes it may be necessary to update the software (software) - flashing FLASH or EEPROM.
When repairing an MB board, you need to check its CPU components: MT5580MPOI, DRAM: NT5CB256M8GN, NAND: TC58NVG2S3ETA00, EEPROM: 24C128. Defective items should be replaced. If BGA chips are installed, their malfunction is usually localized by heating.
Before replacing the TDSY-G230D tuner, if there is no tuning to the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via I2C
We recommend the owners of the 40PFL4528T TV for repair only to qualified specialists with experience! Self-repair attempts without the appropriate knowledge and skills can lead to serious negative consequences!


Service manual and schematic diagram:  40PFL3108T/60 Chassis TPM10.1E LA part1, part2, part3



 The appearance of MainBoard 715G5713-M0F-000-005K is shown in the figure below:
715G5713-M0F-000-005K
715G5713-M0F-000-005K can be used in TVs:
PHILIPS 39PFL3208T/60 (Panel TPT390J1-HJ1L02), PHILIPS 40PFL4418T/60 (Panel LTA400HF30), PHILIPS 40PFL4508T/60 (Panel LTA400HF30 001 SAMSUNG code 186 p/n: 99659004071), PHILIPS 40PFL4528T/60 (Panel LTA400HF30), PHILIPS 32PFL4258T/60 (Panel TPT315B5-HVN01 REV.S210E), PHILIPS 32PFL3258T/60 (Panel TPT315B5-EUJFFA REV:S1A).
PSU Advanced
The 40PFL4528T / 60 model uses a 715G5792-P03-000-002M power supply unit using the PFC (Power Factor Correction) node - an active filter of higher harmonics of the current consumption. In fact, it is a boost converter based on the LD7591T PWM controller, which eliminates the charge current of the electrolytic capacitor of the rectifier filter directly from the network through open diodes when its charging current is determined by its reactance.
As a result of the operation of the converter, the envelope of the high-frequency pulses of the input current of the converter will repeat the shape and phase of the input voltage. The health of the PFC node can be indirectly judged by the presence of an increased constant voltage (about + 380V) on the capacitor of the rectifier network in operating mode.
The appearance of the power supply
Main features of the PHILIPS 40PFL4528T device:
Installed matrix (LED-panel) LTA400HF30.
The matrix control uses the Timing Controller (T-CON) 715G5787-P02-000-002S.
The LED driver 715G5787-P02-000-002S is used to power the backlight LEDs.
The necessary supply voltages for all nodes of the PHILIPS 40PFL4528T TV are generated by the 715G5792-P03-000-002M power supply module or its analogs using LD7591T (PFC), SSC1S311, PF8200S microcircuits and K15A60 type power switches.
MainBoard - the main board (motherboard) is a 715G5713-M0F-000-005K module, using CPU chips: MT5580MPOI, DRAM: NT5CB256M8GN, NAND: TC58NVG2S3ETA00, EEPROM: 24C128 and others.
The TDSY-G230D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTA400HF30-W
Type: a-Si TFT-LCD, Panel
Diagonal size: 40 inch
Resolution: 1920x1080, FHD
Display Mode: S-PVA, Normally Black, Transmissive
Active Area: 885.6x498.15 mm
Surface: Antiglare (Haze 2%), Hard coating (2H)
Brightness: 350 cd / m²
Contrast Ratio: 5000: 1
Display Colors: 1.07B (8-bit + Hi-FRC), CIE1931 70%
Response Time: 8 (G to G)
Frequency: 120Hz (60Hz Input)
Lamp Type: WLED Without Driver
Signal Interface: LVDS (2 ch, 10-bit), 61 pins
Voltage: 12.0V