Thursday, 30 January 2020

REPAIR / SERVICING TV PHILIPS 42PFL3506H

Technical description and composition of the PHILIPS 42PFL3506H TV, type of panel and applicable modules. The composition of the modules.
PHILIPS
Model: 42PFL3506H / 58
Chassis / Version: TPM6.1E LA
Panel: LC420WUY (SC) (B1)
Inverter (backlight): integrated into PSU
MOSFET Inverter: P10NK60
Power Supply (PSU): 715G4802-P01-H20-003H
PWM Power: TNY277PN, FAN6961 (PFC), NCP1271A, UBA2071AT
MOSFET Power: 11N60
MainBoard: 715G4609-M3A-000-005B
IC MainBoard: STA339BW, TMDS251, 17113E
Tuner: TDTK-G731D
Specifications 42PFL3506H
PHILIPS 42PFL3506H
General recommendations for repairing TV LCD
Possible malfunctions
- The PHILIPS 42PFL3506H does not turn on at all. The control lights do not light or flash. The TV on the remote control and the control panel buttons do not respond.
Often in such cases, the 715G4802-P01-H20-003H power module is faulty. It is necessary to verify the presence of its output voltages and, if they are completely absent, check the power switches (11N60) and rectifier diodes for a probable short circuit.
In case of breakdowns in the secondary circuits, the converter, as a rule, can emergency work in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse usually breaks.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode, or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damper circuits, or negative feedback elements in the stabilization circuit. PWM controllers TNY277PN, FAN6961 (PFC), NCP1271A, UBA2071AT, in the absence of visible damage or frank short-circuit between the terminals, are checked by replacing with new, or obviously working.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
These manifestations can be triggered by the power module, or by inverter defects, as well as by the distortion of the currents in the lamps due to their uneven wear. After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, it is necessary to ring in its converter the power switches for breakdown and the secondary windings of the transformers for an open.
If in diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during work, and after they are finished, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the 715G4609-M3A-000-005B motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). In cases of attempts to repair the MB board (SSB), it is necessary to check the serviceability of its elements - STA339BW, TMDS251, 17113E which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its conclusions with the board (it is diagnosed by heating).
Before replacing the TDTK-G731D tuner, if there is no tuning for the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus
Attention! For users and owners of 42PFL3506H TVs who do not have the appropriate qualifications, knowledge and experience, we categorically do not recommend attempting self-repair in order to avoid negative consequences that could lead to complete non-serviceability of the device.

 

Service manual and schematic diagram PHILIPS 42PFL3506H Chassis TPM6.1E LA



 The appearance of the MainBoard 715G4609-M3A-000-005B is shown in the figure below:
715G4609-M3A-000-005B
The appearance of the power supply
Main features of the PHILIPS 42PFL3506H device:
Installed matrix (LCD panel) LC420WUY (SC) (B1).
To power the backlight, a converter is used, combined with a power supply. As power elements of the inverter, keys of the type P10NK60 are used.
The necessary supply voltages for all nodes of the PHILIPS 42PFL3506H TV are generated by the 715G4802-P01-H20-003H power supply module or its analogs using TNY277PN, FAN6961 (PFC), NCP1271A, UBA2071AT, and 11N60 type power switches.
MainBoard - the main board (motherboard) is a module 715G4609-M3A-000-005B, using microchips STA339BW, TMDS251, 17113E and others.
The TDTK-G731D tuner provides television reception and channel tuning.