Friday 31 January 2020

REPAIR / SERVICING TV PHILIPS 42PFL7662D

Technical description and composition of the PHILIPS 42PFL7662D TV, panel type and applicable modules. The composition of the modules.
PHILIPS
Model: 42PFL7662D / 12
Chassis / Version: LC7.2E LA
Panel: LC420WU5 code 093
Inverter (backlight): LC420WU5
PWM Inverter: BD9897FS
MOSFET Inverter: K4075
Power Supply (PSU): PLCD300P3 24573
PWM Power: TEA1601T (16), TEA1533AT (14), L6562D (PFC)
MOSFET Power: 2SK4075, F11NM60N, P4NK60ZFP, P6NK60ZFP
MainBoard: 313912362611 3139 123 62611 313926807405
IC MainBoard: PNX8314HS / 102; K4S281632I; M29W320ET; M30300AGP
Tuner: TD1316AF / IHP-2
Specifications 42PFL7662D
PHILIPS 42PFL7662D
General recommendations for repairing TV LCD
The PHILIPS TV made on the LC7.2E LA chassis, like many other electronic devices, it is advisable to start repairing by inspecting all external and internal elements. Sometimes, based on visible changes in the components of the device, it is possible to draw some conclusions and determine the direction of further troubleshooting even before the necessary measurements are taken. Carbonized paint on the upper layer of resistors, electrolytic capacitors of rectifier filters swollen after boiling, cracked soldering at the terminals of heating elements or transformers can often suggest the cause of the defect and possible consequences.
If the TV does not turn on, no indicators on its front panel are lit or blinking. Also, if the TV does not respond to the remote control and buttons, does not make any sounds or any signs of operability when it is turned on, there is a certain chance that the PLCD300P3 24573 power supply module is defective and needs repair. Sometimes with similar manifestations a problem can only occur in the absence of processor power, which is typical for certain PHILIPS models. When repairing the power supply, it is advisable to start the diagnostics by checking the mains fuse and the electrolytic capacitors of the filters of the converter secondary rectifiers. In the event of a fuse breaking, the reason should be sought in the power semiconductor elements of the pulse converter of the main power supply. First of all, it is necessary to check the diodes of the bridge of the rectifier of the mains voltage and the power key (s) of the K4075 F11NM60N P4NK60ZFP P6NK60ZFP converter.
The reasons for the breakdown of the power switch in switching power supplies (IIPS) can be different, for example, a malfunction of semiconductor elements or electrolytic capacitors in the stabilization circuits of the primary circuit, as well as a failure in the operation of the TEA1601T (16), TEA1533AT (14) PWM controller chip, L6562D (8) or breakage of resistors in its harness.
If the PHILIPS 42PFL7662D does not have an image, there is sound and the channels are switched, there is a possibility of a malfunction of the display backlight, or their power converter - inverter. Sometimes when you turn on the image appears and disappears immediately. In such cases, it is necessary to check the electrolytic capacitors of the power filter of the inverter itself, including in the secondary rectifier of the main PSU. When disabling the inverter protection (to enable diagnostics), special care must be taken in view of the risk of failure of the power elements. After completing all repair work, it is imperative to restore the protection circuits for full and safe further operation of the TV by the user.
Owners and users of the PHILIPS 42PFL7662D TV must remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!


Service manual and schematic diagram -------------------------> 42PFL7662D/12 Chassis LC7.2E LA

 PSU SCHEMATIC --------------->  PLCD300P3.

 The appearance of MainBoard 313912362611 is shown in the figure below:
313912362611
313912362611 can be used in TVs:
PHILIPS 26HF5445/10 (Panel V260B1-L03 code 068 p/n: 932224937682), PHILIPS 37PFL7662D/12 (Panel T370HW02 V.1), PHILIPS 42PFL7662D/12 (Panel LC420WU5 code 093), PHILIPS 42PFL7682D/12 (Panel LC420WU5), PHILIPS 47PFL5522D/12 (Panel LC470WX1-SLA2 code 109 p/n: 932225331682 (LGPH) B ), PHILIPS 32PFL5522D/12 (Panel LK315T3LZ53).
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the PLCD300P3 module provides for the use of a Power Factor Correction unit. The PFC circuit is a flyback converter based on the L6562D 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 42PFL7662D device:
Installed matrix (LCD panel) LC420WU5 code 093.
An LC420WU5 inverter is used to power the backlight, controlled by the BD9897FS PWM controller. As power elements of the inverter, keys of the K4075 type are used.
The necessary supply voltages for all nodes of the PHILIPS 42PFL7662D TV are generated by the PLCD300P3 power supply module or its analogs using TEA1601T (16), TEA1533AT (14), L6562D (PFC) microcircuits and power switches of the type 2SK4075, F11NM60N, P4NK60ZFP, P6NP60.
MainBoard - the main board (motherboard) is a module 313912362611, using PNX8314HS / 102 microcircuits; K4S281632I; M29W320ET; M30300AGP and others.
The TD1316AF / IHP-2 tuner provides TV reception and channel tuning.