Technical description and composition of the PHILIPS 32PFL7864H TV, type of panel and applicable modules. The composition of the modules.PHILIPS
Model: 32PFL7864H / 60
Chassis / Version: Q548.1E LA
Panel: LC320WUF-SBN1
T-CON: 6870C-4000H LC320WU
Inverter (backlight): integrated into PSU
PWM Inverter: OZ9966GN
Power Supply (PSU): PLHL-T826 A 272217100788
PWM Power: L6599D (PWM Resonant), FAN7530 (PFC)
MOSFET Power: 2SK3561, FDD5N50
MainBoard: 3139_123_64423V2 3139_123_64433V2 314302713646
IC MainBoard: PNX8539EH24182, LAN9420-NU, TDA9996HL / C4
Tuner: HD1816AF / BHXP
Specifications 32PFL7864H
PHILIPS 32PFL7864H
General recommendations for repairing TV LCD
Repair of the PHILIPS 32PFL7864H / 60 TV is advisable to start with a careful external examination. In this case, both external and internal components of the device should be inspected. Often, by visible changes, it is possible to determine the further direction of troubleshooting and localization of the defect before the start of the acquisition of oscillograms and the necessary measurements. In some cases, faulty elements can be seen with the naked eye, for example, charred resistors or swollen metal-ceramic capacitors, or electrolytic in rectifier filters. Ring cracks formed in the soldered terminals of transformers or heating elements of the circuit are also frequent sources of many malfunctions with a variety of external manifestations.
Power Module Repair
Sometimes the PHILIPS 32PFL7864H / 60 TV simply does not turn on. No control lights on the front panel are lit or blinking, the TV does not respond to the remote control and does not make any sounds or any signs of life when turned on. The most likely cause of the malfunction is the failure of the common PLHL-T826A power supply module. It is advisable to start the troubleshooting of the power supply module by checking the state of the electrolytic capacitors of the rectifier filters and the mains fuse. Defective capacitors should be replaced. If the mains fuse is broken, it is necessary to check first of all the power semiconductor elements - rectifier diodes and the power switch of the converter, which are often found in breakdown conditions in such situations.
It should be borne in mind that in the practice of repair it is extremely rare that key transistors of the N-FET type fail for no reason to be looked for by checking other components, for example, a breakdown of the key can provoke faulty elements of the damper circuits, either dried electrolytic capacitors or dangling resistors of the primary circuit of the PSU, involved in the stabilization process. In this case, all semiconductor elements of the strapping of the PWM controller chip are subject to verification, which it is desirable to verify by replacement.
It is somewhat more difficult to find faults in the converter of the power module with an active KKM (power factor corrector).
Inverter Repair
If the PHILIPS 32PFL7864H / 60 TV does not have an image, but there is sound, the malfunction should be sought in the backlight power converter (inverter). It is also necessary to check the serviceability of the electrolytic capacitors of the filter of the secondary rectifiers of the PSU (power supply) for an overstated ESR.
Diagnostics and repair of the inverter are often complicated by the organization of special protection circuits, which is necessary for fire safety and turns off the inverter in any emergency situation, for example, when the lamps are worn or depressurized. Often, to block a defect, it needs to be locked.
It should be remembered that when the protection is turned off, there is always a risk of failure of the inverter power elements during diagnosis. After repair, it is necessary to restore all standard converter protection circuits.
Repair Main Board
On the motherboard, in the event of a malfunction, you should first check the supply voltage and the performance of all the stabilizers or power converters of the microcircuits and, if necessary, update the software (software).
Owners of the 32PFL7864H / 60 TV are recommended for repairing contact only qualified specialists with experience! Self-repair attempts without the appropriate knowledge and skills can lead to serious negative consequences!
Service manual and schematic diagram 32PFL7864H/60 Chassis Q548.1E LA
The appearance of MainBoard 3139_123_64423V2 is shown in the figure below:3139_123_64423V2
3139_123_64423V2 can be used in TVs:
PHILIPS 32PFL7864H/60 (Panel LC320WUF-SBN1), PHILIPS 32PFL8404H/60 (Panel LC320WUF (SB)(N1) code 181 p/n: 932226687682), PHILIPS 37PFL8404H/60 (Panel T370HW03 V.2 code 189), PHILIPS 42PFL7674H/60 (Panel LC420WUF(SB)(N1)), PHILIPS 42PFL7864 (Panel 42 ), PHILIPS 42PFL8404H/60 (Panel LC420WUF-SBN1 code 183 p/n: 932226646682).
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the PLHL-T826 module provides for the use of a Power Factor Correction unit. The PFC circuit is a flyback converter based on the FAN7530 PWM controller. The reactance of an electrolytic capacitor of a line filter at a frequency of 50-60 Hz is usually not more than 20-30 ohms and its charge directly from the network through open diodes could reach tens of amperes per pulse if no filtering was applied.
As a result of the PFC conversion, an increased voltage on the capacitor (about 380V) cannot directly open the rectifier diodes, on the anode of which the voltage will always be slightly less (about 300V) and then its charging current will always be limited by the elements of the PWM controller. As a result, the envelope of the high-frequency pulses of the consumed current will repeat the shape and phase of the input sinusoidal voltage. The presence of an increased voltage (+ 380V) on the network capacitor indicates the serviceability of the PFC node.
The appearance of the power supply
Main features of the PHILIPS 32PFL7864H device:
Installed matrix (LCD panel) LC320WUF-SBN1.
The matrix control uses the Timing Controller (T-CON) 6870C-4000H.
To power the backlight, a converter is used, combined with a power supply, controlled by the OZ9966GN PWM controller.
The necessary supply voltages for all nodes of the PHILIPS 32PFL7864H TV are generated by the PLHL-T826 power module or its analogs using L6599D (PWM Resonant), FAN7530 (PFC) microcircuits and 2SK3561, FDD5N50 type power switches.
MainBoard - the main board (motherboard) is a module 3139_123_64423V2, using chips PNX8539EH24182, LAN9420-NU, TDA9996HL / C4 and others.
The HD1816AF / BHXP tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC320WUF-SBN1
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1920x1080, FHD
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 698.4x392.85 mm
Surface: Antiglare (Haze 10%), Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 1300: 1
Display Colors: 1.06B (8-bit + FRC)
Response Time: 6 (G to G)); 8 (MPRT)
Frequency: 120Hz
Lamp Type: 16 pcs EEFL Without Driver
Signal Interface: LVDS (4 ch, 10-bit), 92 pins
Voltage: 12.0V