Saturday, 25 January 2020

REPAIR / SERVICING TV PHILIPS 32PF9976

Technical description and composition of the PHILIPS 32PF9976 TV, type of panel and applicable modules. The composition of the modules.
PHILIPS
Model: 32PF9976 / 12
Chassis / Version: FTL2.2E AA
Panel: LC320W01-A6K1
Inverter (backlight): 6632L-0066B
PWM Inverter: LX1688IPW
MOSFET Inverter: FDS6690A
Trans Inverter: SSB LCD32 LPL 2K4 3104 328 37513
Power Supply (PSU): 3104_313_60095 3104 313 60095 3104 328 27462
PWM Power: MC34067P (16)
MOSFET Power: STP15NK50ZFP
MainBoard: 3104_303_38944
IC MainBoard: TDA9321H, SAA4978H, EP1C12F256C8, MSN56V16160F
Tuner: UV1318S / AIH-3
Specifications 32PF9976
PHILIPS 32PF9976
General recommendations for repairing TV LCD
It is advisable to start any repair and diagnostics of the PHILIPS 32PF9976 / 12 TV, as well as other devices, with a careful external examination of internal and external elements, including case parts, a display, buttons, and cables. 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. Swollen electrolytic or cermet capacitors, charred resistors, ring cracks in the soldered terminals of the elements - all this can significantly help the master to determine the causes and consequences of the malfunction of the TV.
Power Module Repair
Sometimes the PHILIPS 32PF9976 / 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 PSU common power module. 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 switch 2K4 3104 328 30012 is detected, which can be integrated with the 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.
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. The PWM controller microcircuit 32 can also cause a breakdown of the power switch of the converter.
In cases where the Power Factor Corrector (PFC) is used in the power supply, troubleshooting can be a bit more complicated.
Inverter Repair
If, when you turn on the TV, the image appears and immediately disappears, or is initially absent when you turn on, but there is sound and other functions work, there is a high probability of a malfunction of the inverter (power converter for the backlight). In such cases, the lamps, the inverter and the common power module are subject to verification, in which the electrolytic capacitors of the rectifier filter supplying the inverter should be checked.
Repair of the inverter 6632L-0066B + XXXXX can often be somewhat complicated by the use of special protection circuits, which are designed to disconnect it in emergency cases for fire safety when the lamps are depressurized, or short circuits or breaks in high-voltage circuits and connections. Sometimes it becomes necessary for diagnostic purposes to block the protection circuits in order to be able to make the necessary measurements at the control points of the circuit.
When diagnosing with the protection off, special precautions must be taken, because there is a risk of failure of the power elements of the inverter. After the diagnosis, it is imperative to restore the protection circuits for the inverter to operate normally.

Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repair only to professionals with sufficient experience in the field of electronic equipment repair.


Service manual and schematic diagram 32PF9976/12 Chassis FTL2.2E AA


 The appearance of MainBoard 3104_303_38944 is shown in the figure below:
3104_303_38944
3104_303_38944 can be used in TVs:
PHILIPS 32PF9976 / 12 (Panel LC320W01-A6K1), PHILIPS 32PF9986 / 12 (Panel LQ315T31.Z13).
The appearance of the power supply
Main features of the PHILIPS 32PF9976 device:
Installed matrix (LCD panel) LC320W01-A6K1.
To power the backlight, an inverter 6632L-0066B is used, it is controlled by the LX1688IPW PWM controller. An SSB LCD32 LPL 2K4 3104 328 37513 transformer is installed in the inverter converter. Keys of the FDS6690A type are used as power elements of the inverter.
The necessary supply voltages for all nodes of the PHILIPS 32PF9976 television are generated by the power supply module 3104_313_60095, or its analogs using MC34067P microcircuits (16) and power switches of the STP15NK50ZFP type.
MainBoard - the main board (motherboard) is a module 3104_303_38944, using chips TDA9321H, SAA4978H, EP1C12F256C8, MSN56V16160F and others.
The UV1318S / AIH-3 tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG.Philips LCD
Model: LC320W01-A6K1
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 697.68x392.26 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 600: 1
Display Colors: 16.7M (8-bit)
Response Time: 8/10 (Tr / Td)
Frequency: 60Hz
Lamp Type: 20 pcs EEFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V