
PHILIPS
Model: 26PF5521
Chassis / Version: LC4.31E AB
Panel: PLCD170P2
Power Supply (PSU): PLCD170P2 3122 137 23191 // DPS-160NP
PWM Power: NCP1207A (8pin PWM), DLA001D (PWM = L6598), L6562D (PFC), EZ09638 (14pin)
MainBoard: 3139-123-6117.2 WK542.2
IC MainBoard: gm1501-LF-M4747CF_0710S, TDA15021H / N1C91, M29W400DT
Tuner: UL1318S / AI H-3
Specifications 26PF5521D
PHILIPS 26PF5521
General recommendations for repairing TV LCD
Like all other TVs, PHILIPS 26PF5521 it is advisable to start repairing with a careful inspection of both external and internal elements and modules. Often, according to the external signs and the nature of some damage to the elements, it is possible to draw preliminary conclusions and determine a further algorithm for troubleshooting and localizing the malfunction before carrying out the necessary measurements and taking oscillograms at control points. If ring cracks are detected in the soldering of the terminals of the elements or dangling connecting tracks, swollen capacitors or charred resistors - all this can be characteristic signs of the causes or consequences of an already known typical malfunction.
Power Module Repair
In the absence of any signs of operability, when the PHILIPS 26PF5521 does not turn on and does not signal anything with the control lights on the panel, the DPS-160NP power supply module is most likely faulty. 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 cause should be sought in the power semiconductor elements of the pulsed flyback converter of the main power supply unit. First of all, it is necessary to check the diodes of the bridge of the rectifier of the mains voltage and the power switch of the converter, which can be installed separately on the radiator, or integrated with a PWM controller.
It should be remembered that the N-FET keys used in flyback converters rarely fail without their own sake without any reasons that must be sought by checking other elements of the circuit. Often the breakdown is caused by malfunctions of electrolytic capacitors or semiconductor elements in the primary circuit, or by a break in the resistors in the stabilization circuits. Integrated circuit PWM controller 1207A (8n) Sq. DLA001D (16H) PL (L6598). L6562D (8n) pl. EZ09638 (14H) PL can also be the cause of the breakdown of the power switch of the converter.
When using a power factor correction unit (PFC) in the power modules, troubleshooting becomes somewhat more complicated and requires additional experience and knowledge of their operation.
Inverter Repair
In cases where the PHILIPS 26PF5521 TV has lost an image, and the sound is there and all the other functions are operational, there is a possibility of a malfunction of the inverter (converter for powering the backlight). When you turn on the TV, the image may appear briefly and immediately disappear. It must be borne in mind that with such manifestations, the lamps themselves also fail, the malfunction of which can be detected by replacement, by connecting to the connectors for diagnostics that are known to be serviceable and suitable in power.
Diagnostics of the inverter can be difficult due to the operation of the protection, which is organized by the designers to prevent negative consequences or fires in emergency cases, for example, during short circuits or breaks in the lamp power supply circuit, as well as their possible depressurization. To make the necessary measurements at control points or to take the necessary waveforms, repairmen have to block the protection circuits in order to be able to diagnose.
Turning off the protection for diagnostic purposes, it must be remembered that in this case there is a risk of failure of the power elements of the inverter. Upon completion of the diagnosis, all regular protection circuits should be restored.
Remember! Attempts to self-repair by users of the PHILIPS 26PF5521 TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!
Service manual and schematic diagram 26PF5521 Chassis LC4.31E AB

3139-123-6117.2
3139-123-6117.2 can be used in televisions:
PHILIPS 26PF4311S/10 (Panel LC260WX2(SL)(B2)), PHILIPS 26PF5521 (Panel PLCD170P2), PHILIPS 26PF7321/12 (Panel LC260WX2-SL04), PHILIPS 32PF4311S/10 (Panel LC320W01 (sl)(06)), PHILIPS 32PF4311S/10 (Panel LC320W01(SL)(06)), PHILIPS 32PF5331/12 (Panel T315XW01 V9), PHILIPS 32PF7321 (Panel LC320W01), PHILIPS 32PF7331/12 (Panel LC320W01), PHILIPS 32PFL3321S/60 (Panel LC320W01 (SL)(06)), PHILIPS 37PFL3321/10 (Panel LC370WX1-SL04), PHILIPS 32PF3321/12 (Panel CLAA320WB02 (P)), PHILIPS 37PF3321/12 (Panel LC370WX1 (SL)(04)).
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the PLCD170P2 module provides for the use of a power factor correction unit (Power Factor Correction). 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 were 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 26PF5521 device:
Installed matrix (LCD-panel) PLCD170P2.
The required supply voltages for all nodes of the PHILIPS 26PF5521 TV are generated by the PLCD170P2 power module or its analogs using NCP1207A (8pin PWM), DLA001D (PWM = L6598), L6562D (PFC), EZ09638 (14pin) microcircuits.
MainBoard - the main board (motherboard) is a module 3139-123-6117.2, using microchips gm1501-LF-M4747CF_0710S, TDA15021H / N1C91, M29W400DT and others.
The UL1318S / AI H-3 tuner provides TV reception and channel tuning.