Friday 31 January 2020

REPAIR / SERVICING TV PHILIPS 42PFL4606H

Technical description and composition of the PHILIPS 42PFL4606H TV, type of panel and applicable modules. The composition of the modules.
PHILIPS
Model: 42PFL4606H / 60
Chassis / Version: TPM7.1E LA
Panel: LC420WUY SCA1
Inverter (backlight): integrated into PSU
PWM Inverter: UBA2071AT
MOSFET Inverter: TF10N60
Trans Inverter: 080GL52T929 TMS94876CT
Power Supply (PSU): 715G4546-P03-H20-003E
PWM Power: TOP264VG, FAN6961 (PFC), NCP1271 (Standby)
MainBoard: 715G4481-M02-000-005X, 715G4481-M01-000-005X
IC MainBoard: CPU: MT5395LHGJ, DDR: NT5CB64M16AP, Nand: HY27UF082G2B, SPI Flash: MX25L4005AMI-12G
Tuner: ENV57U09D5F
Specifications 42PFL4606H
PHILIPS 42PFL4606H
General recommendations for repairing TV LCD
PHILIPS with the TPM7.1E LA chassis, like other televisions, it is advisable to start repairing with a careful examination of the external and internal elements and modules. Using visible changes in the state of components, it is usually possible to determine the further direction of troubleshooting and localization of the defect 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 power supply module 715G4546-P03-H20-003E malfunctions, the external manifestations may be different, for example, the PHILIPS 42PFL4606H does not turn on at all and there is no indication of the indicator lights on the front panel. With the same symptoms, the stabilizer (converter) of the power supply to the control processor may be faulty. In the general case, first of all, it is necessary to check the electrolytic capacitors of the secondary rectifier filters and the fuse at the input of the network. If it is broken, then you should check for breakdown of the PN junctions of the rectifier bridge diodes and the key transistor of the converter, which can either be on a separate radiator or integrated with a PWM controller in a common chip. Possible options.
Power switches in pulsed power supplies (SMPS) 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.
Sometimes the PHILIPS 42PFL4606H TV does not have an image, but there is sound, or the image appears and immediately disappears. In this case, there is a high probability of a malfunction of the backlight converter, or of the lamps themselves, which can be checked by replacement. In such cases, it is necessary to verify the serviceability of all electrolytic capacitors of the filter according to the power supply of the inverter itself, including the power supply unit (power supply unit). When diagnosing a malfunction of the inverter 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.
If the motherboard 715G4481-M02-000-005X 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.
Remember! Attempts to self-repair by users of the PHILIPS 42PFL4606H TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!


Service manual and schematic diagram42PFL4606H/60 Chassis TPM7.1E LA

 The appearance of the MainBoard 715G4481-M02-000-005X is shown in the figure below:
715G4481-M02-000-005X
715G4481-M02-000-005X can be used in TVs:
PHILIPS 42PFL4606H/60 (Panel LC420WUY SCA1), PHILIPS 32PFL4606H/60 (Panel LC320WUY (SC)(A1)).
PSU Advanced
The 42PFL4606H / 60 TV is equipped with a 715G4546-P03-H20-003E power module using the PFC (Power Factor Correction) circuitry acting as an active filter to eliminate the higher harmonic components of the current consumption. The boost converter based on the FAN6961 PWM controller does not allow the electrolytic capacitor of the input rectifier filter to be connected directly to the network directly through open diodes, when the value of the charge current determines its reactance (about 15-30 ohms at a frequency of 50 Hz). As a result of the conversion, the charging current of the capacitor will be determined in such a way that the envelope of the high-frequency pulses of the input current will repeat the phase and shape of the sine wave of the input voltage. The health check of the PFC unit is carried out by measuring the DC voltage on the capacitor of the rectifier network. In operating mode, it should be around 380V, in standby approximately 300V.
The appearance of the power supply
Main features of the PHILIPS 42PFL4606H device:
Installed matrix (LCD panel) LC420WUY SCA1.
To power the backlight, a converter is used, combined with a power supply, controlled by a UBA2071AT PWM controller. The transformer 080GL52T929 TMS94876CT is installed in the inverter converter. As power elements of the inverter, keys of the type TF10N60 are used.
The necessary supply voltages for all nodes of the PHILIPS 42PFL4606H TV are generated by the 715G4546-P03-H20-003E power module, or its analogs using TOP264VG, FAN6961 (PFC), NCP1271 (Standby) microcircuits.
MainBoard - the main board (motherboard) is a 715G4481-M02-000-005X module using CPU chips: MT5395LHGJ, DDR: NT5CB64M16AP, Nand: HY27UF082G2B, SPI Flash: MX25L4005AMI-12G and others.
The ENV57U09D5F tuner provides TV reception and channel tuning.