Saturday 1 February 2020

REPAIR / SERVICING TV PHILIPS 42PFL6805H

Technical description and composition of the PHILIPS 42PFL6805H TV, type of panel and applicable modules. The composition of the modules.
PHILIPS LED
Model: 42PFL6805H / 60
Chassis / Version: Q551.1E LA
Panel: LC420EUH (SC) (G1)
LED backlight: 3660L-0357A 42 V5 Green Edge REV1.0 2 A-Type / B-Type
LED driver (backlight): integrated into PSU
PWM LED driver: BD9211F
Power Supply (PSU): PLDF-P991A / 2722 171 90264/2722 171 90264
PWM Power: LNK362PG (7), L6599AD, FA5591
MOSFET Power: MDF9N50, MDF5N50, MDD5N50
MainBoard: 3104_313_64731 - 3104 313 64731/3104 328 64741
IC MainBoard: TL2429MC, TPA23D2, 17113E, 4952, RT8250, 4778
Tuner: TH2603
Control: Remote: 2422 549 90285, IR: 41 64612
Specifications 42PFL6805H
PHILIPS 42PFL6805H
General repair guidelines for TV LCD LED
PHILIPS 42PFL6805H / 60, like other televisions, it is advisable to start repairing with a careful examination of the external and internal elements and modules. It often happens that visible damage to elements or connections helps determine the direction of the troubleshooting. If ring cracks are detected in the soldering of the terminals of the elements or dangling connecting tracks, swollen capacitors or charred resistors - all this can be characteristic signs of the causes or consequences of an already known typical malfunction.
In the case when the 42PFL6805H does not turn on, does not respond to the remote control and the front panel buttons, does not blink bulbs and does not show any signs of operability, the power supply module 2722 171 90264 PLDF-P991A 2722 171 90264 is probably faulty in this case. manifestations, it is necessary to check the stabilizer (converter) of the processor power supply on the motherboard. In the absence of swollen filter capacitors of the secondary rectifiers, the diagnostics of the power supply should be started by checking the fuse and, if it is broken, it is necessary about in the first place to check all the power semiconductor elements of the primary circuit - diodes and transistors MDF9N50, MDF5N50 the likelihood of avalanche or thermal breakdown.
The reasons for the breakdown of the power switch in switching power supplies (IIPS) can be different, for example, a malfunction of semiconductor cells or electrolytic capacitors in the stabilization circuits of the primary circuit, as well as a failure in the operation of the PWM controller LNK362PC (7) 1023, or breakage of the resistors in it strapping.
Sometimes the PHILIPS 42PFL6805H 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 LC420EUH (SC) (G1) panel LED backlight converter, or a break in the LED circuit is possible. In such cases, first of all, it is necessary to verify the serviceability of all the electrolytic capacitors of the filter by supplying the LED driver itself, including in the power supply unit (power supply unit).
Often there is a need for disassembling the panel to check the health of the LEDs, as well as contact connections in the connectors and soldering.
When diagnosing, it is necessary to take into account that it is impossible to check the open in the chain of LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally, a current source.
On the motherboard 3104 328 64741, in the event of a malfunction, you should first check the performance of all the stabilizers or power converters of the microcircuits and, if necessary, update the software (software).
If it is not possible to replace the MB (SSB) card, it is necessary to check the health of its elements - TL2429MC, TPA23D2, 17113E, 4952, RT8250, 4778. Faulty components should be replaced.
Attention to users! Self-repair of a PHILIPS 42PFL6805H TV without the appropriate qualifications and experience can lead to its complete non-repairability!


Service manual and schematic diagram 42PFL6805H/60 Chassis Q551.1E LA


 The appearance of MainBoard 3104_313_64731 is shown in the figure below:
3104_313_64731
3104_313_64731 can be used in TVs:
PHILIPS 42PFL6705H/60 (Panel LC420EUH(SC)(G1)), PHILIPS 42PFL6805H/60 (Panel LC420EUH (SC)(G1)).
The appearance of the power supply
Main features of the PHILIPS 42PFL6805H device:
Installed matrix (LED-panel) LC420EUH (SC) (G1).
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by a BD9211F PWM controller.
The necessary supply voltages for all nodes of the PHILIPS 42PFL6805H TV are generated by the PLDF-P991A power supply module or its analogs using LNK362PG (7), L6599AD, FA5591 microchips and power switches of the MDF9N50, MDF5N50, MDD5N50 type.
MainBoard - the main board (motherboard) is a module 3104_313_64731, using microcircuits TL2429MC, TPA23D2, 17113E, 4952, RT8250, 4778 and others.
The TH2603 tuner provides TV reception and channel tuning.