Technical description and composition of the PHILIPS 32PF9946 TV, type of panel and applicable modules. The composition of the modules.PHILIPS
Model: 32PF9946 / 12
Chassis / Version: LC4.2E AA
Panel: LC230W01-A2K8
PWM Inverter: BIT3106 (BIT3106A)
MOSFET Inverter: 4532GM (ME4542)
Power Supply (PSU): PLCD150P1 23071
PWM Power: L6562D (PFC), TEA1601T (16pin), TEA1533AT (14pin)
MainBoard: 3139-123-5804.2 WK415.1
IC MainBoard: CPU: TDA12029H; DRAM: K4D263238M-QC50;
Tuner: UR1316 / A I H-3
Appearance
PHILIPS 32PF9946
General recommendations for repairing TV LCD
It is advisable to start the repair of the PHILIPS 32PF9946 / 12 TV with a careful external examination of all its components and modules. Also subject to inspection are body elements, functional control buttons, screen, cords and connectors. Often, by the external signs and 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 making the necessary measurements and taking oscillograms at control points. 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 32PF9946 / 12 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 PLCD150P1 23071 power supply module. When diagnosing and repairing the power supply, after replacing the swollen capacitors of the secondary rectifier filters (if any), you must first check the mains fuse. When it is broken, the power switch and rectifier bridge diodes should be checked for avalanche (thermal) breakdown.
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 microcircuit bp L6562D (8n PL) TEA16017 (16n PL) TEA1533AT (14n PL), which it is desirable to check by replacement, are subject to verification.
When using an active Power Factor Correction (CMC) circuit in the power module, the search for faulty elements is somewhat more complicated.
Inverter Repair
If there is no image when turning on the PHILIPS 32PF9946 / 12, or it appears for a second and disappears completely, but there is sound, most likely either the backlight or their power converter (inverter) are faulty. It is necessary to check the electrolytic capacitors of the filter of the secondary rectifiers in the general power supply unit.
The operation of the power circuits of the inverter and the backlight in the normal mode are controlled by special protection, which is organized for fire safety, for example, to disconnect during short circuits or breaks in high voltage connections or when the lamps are depressurized. This protection makes it difficult to diagnose and repair the inverter.
It should be remembered that in such cases there is a risk of failure of the power elements of the inverter and to take special care. After carrying out repairs, the protection circuit must be restored for further safe operation of the TV.
Repair Main Board
If the SSB LC4.2 motherboard is faulty, first of all it is necessary to check all the linear stabilizers or power converters of its chips, and also, if necessary, update the software. Sometimes you can check the health of MB only by replacement.
Owners and users of the PHILIPS 32PF9946 / 12 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 32PF9946/12 Chassis LC4.2E AA
17PF9946/12, 23IF9946/12, 23PF9956/12, 23PF9946/12, 26PF9956/12, 26PF9320/10, 26PF8946/12, 26PF9946/12
The appearance of MainBoard 3139-123-5804.2 is shown in the figure below:3139-123-5804.2
3139-123-5804.2 can be used in televisions:
PHILIPS 23PF9956/12 (Panel LC230W01-A2 K8), PHILIPS 26PF9946/12 (Panel LC260W01-A5K8), PHILIPS 32PF9946/12 (Panel LC230W01-A2K8).
PSU Advanced
The PLCD150P1 power supply module is made using a Power Factor Correction (PFC) scheme to eliminate multiple AC harmonics introduced into the power supply by the device. The PFC assembly is a Step-Up Converter based on the L6562D PWM controller, which evenly distributes high-frequency impulses of the charging current of the electrolytic capacitor of the rectifier filter of the mains voltage over a period of 50 Hz. The current of its charge in this case will already be determined not by its reactance (usually 10-30 ohms for the network frequency), but by the elements of the converter. As a result, a change in the amplitude of the pulses (envelope) of the consumed current of the converter will repeat the shape and phase of the input sinusoidal voltage. The availability of an increased voltage (about + 380V) in the operating mode on the capacitor of the line filter indicates the serviceability of the PFC node.
The appearance of the power supply
Main features of the PHILIPS 32PF9946 device:
Installed matrix (LCD panel) LC230W01-A2K8.
A converter controlled by the BIT3106 PWM controller (BIT3106A) is used to power the backlight lamps. As power elements of the inverter, keys of the type 4532GM (ME4542) are used.
The necessary supply voltages for all nodes of the PHILIPS 32PF9946 TV are generated by the PLCD150P1 power supply module or its analogs using L6562D (PFC), TEA1601T (16pin), TEA1533AT (14pin) microcircuits.
MainBoard - the main board (motherboard) is a module 3139-123-5804.2, using CPU chips: TDA12029H; DRAM: K4D263238M-QC50; and others.
The tuner UR1316 / A I H-3 provides the reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: LG.Philips LCD
Model: LC230W01-A2K8
Type: a-Si TFT-LCD, Panel
Diagonal size: 23.0 inch
Resolution: 1280x768, WXGA
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 501.12x300.67 mm