Saturday, 25 January 2020

REPAIR / SERVICING TV PHILIPS 32PF9986

Technical description and composition of the PHILIPS 32PF9986 TV, panel type and applicable modules. The composition of the modules.
PHILIPS
Model: 32PF9986 / 12
Chassis / Version: FTL2.1E AA
Panel: LQ315T31.Z13
Power Supply (PSU): 3104_313_60095 3104 313 60095 3104 328 27462
PWM Power: MC34067P
MOSFET Power: STP15NK50
MainBoard: 3104_303_38944 3104 303 38944 3104 303 3894.4
IC MainBoard: TDA9321H, SAA4978H, EP1C12F256C8, MSN56V16160F
Tuner: UV1318S / AIH-3
Specifications 32PF9986
PHILIPS 32PF9986
General recommendations for repairing TV LCD
It is advisable to start any repair and diagnostics of the PHILIPS 32PF9986 / 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. Many visible changes make it possible to determine the future direction of troubleshooting and localization of the defect. Electrolytic capacitors of filters with a swollen casing, as well as ring cracks formed in the soldered leads of heating elements, or a layer of coal on burnt resistors sometimes tell the repairman the causes of the malfunction and possible consequences.
Power Module Repair
In the absence of any signs of operability, when the PHILIPS 32PF9986 / 12 does not turn on and does not signal anything with the control lights on the panel, the power module is most likely faulty. 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.
Power switches in flyback converters fail extremely rarely for no reason and, if they are broken, it is necessary to look for a malfunction in the stabilization circuits by checking electrolytic capacitors, semiconductor devices, and resistors in the primary circuit. The cause may be a malfunction of the PWM controller chip, which can only be checked by replacing it with a new or obviously working one.
If an active Power Factor Corrector (PFC) is used in the power module circuitry, it is sometimes more difficult to troubleshoot. Knowledge, experience, intuition and skills in such cases have a great advantage for a successful repair.
Inverter Repair
If the PHILIPS 32PF9986 / 12 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.
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.
In such cases, special care should be taken during diagnostics, and after completion of all repair work, it is necessary to restore the circuit and the inverter protection for further safe operation of the TV.
For 32PF9986 / 12 TV owners, we recommend that you contact qualified personnel with experience to repair! Self-repair attempts without the appropriate knowledge and skills can lead to serious negative consequences!


Service manual and schematic diagram 32PF9986/12 Chassis FTL2.1E 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 32PF9986 device:
Installed matrix (LCD panel) LQ315T31.Z13.
The necessary supply voltages for all nodes of the PHILIPS 32PF9986 television are generated by the power supply module 3104_313_60095, or its analogs using MC34067P microcircuits and power switches of the STP15NK50 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.