Saturday, 1 February 2020

REPAIR / SERVICING TV PHILIPS 42PFL7108S

Technical description and composition of the PHILIPS 42PFL7108S TV, type of panel and applicable modules. The composition of the modules.
PHILIPS LED
Model: 42PFL7108S / 60
Chassis / Version: QFU1.2E LA
Panel: LC420EUF PFF1
LED backlight: 6920L-0001C, 6922L-0072A; 925mm 57 LED * 2
T-CON: PH_120PSQBC4LV1.0 LPF1280
LED driver (backlight): integrated into PSU
PWM LED driver: BD9479FV
Power Supply (PSU): FSP140-4FS01, 2722 171 90775 Rev 00
PWM Power: FSB117H (Standby 8pin), FAN7930 (PFC), SSC9522S (PWM resonant)
MainBoard: 310431366185 3104 313 66185 310432882021 YU 332.8 AI1.C
IC MainBoard: FUSION120, H5TQ2G63BFR, H5TQ2G83BFR
Tuner: SUT-RE214AN
Specifications 42PFL7108S
PHILIPS 42PFL7108S
General repair guidelines for TV LCD LED
Diagnostics of malfunctions and repairs PHILIPS 42PFL7108S / 60, as well as other electronic devices, it is recommended to start with an external examination of the external and internal elements. Visible damage to the elements can sometimes indicate the direction of the search for the defect even before the necessary measurements. Elements with visible damage, for example, capacitors swelled up after boiling the electrolyte, charred resistors in certain nodes of the circuit, as well as ring cracks in solders will help the master to guess the causes and possible consequences of the malfunction.
If the power supply module FSP140-4FS01, 2722 171 90775 Rev 00 fails, the external manifestations may be different, for example, PHILIPS 42PFL7108S 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 absence of swollen filter capacitors of the secondary rectifiers, the diagnostics of the power supply should begin by checking the fuse and, if it is broken, it is first necessary to check all the power semiconductor elements of the primary circuit - diodes and transistors for the possibility of an avalanche or thermal breakdown.
It should be remembered that in the practice of repair, usually the power switches in switching power supplies (SMPS) do not fail due to their poor quality and, in such cases, it is necessary to look for the cause that led to a malfunction and provoked a breakdown of the key. Most often, the culprits of the accident are dried electrolytic capacitors or dangling resistors in the primary circuit, or the PWM controller chip itself may be faulty. It is also necessary to check all the semiconductor elements of the stabilization circuit in the primary and secondary circuits.
In cases where the PHILIPS 42PFL7108S TV has lost an image, and the sound is there and all other functions are operational, there is a possibility of a malfunction of the LED driver (converter for powering the backlight LEDs of the LC420EUF PFF1 panel). When you turn on the TV, the image may appear briefly and disappear immediately. It must be borne in mind that with such manifestations the LEDs themselves also fail.
In most cases of lack of backlight, it becomes necessary to disassemble the panel in order to check the LEDs, connectors, loops and all contact connections. If one or several LEDs does not work in one line, therefore, they are broken and should be replaced.
To check the LED lines for breaks without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter, a voltage of the order of several tens of volts is required.
When trying to repair the motherboard, you should first check the serviceability of linear stabilizers or power converters of microcircuits and, if necessary, update the software (software).
The malfunction of the SUT-RE214AN tuner is established after checking the software and all the supply voltages at its terminals, including the varicap supply voltage (30-33V).
Attention to users! Self-repair of a PHILIPS 42PFL7108S TV without the appropriate qualifications and experience can lead to its complete non-repairability!


Service manual and schematic diagram 42PFL7108S/60 Chassis QFU1.2E LA


CHASSIS QFU1.2E LA FOR MODELS OF  TV PHILIPS:
40PFL8008K, 40PFL8008S
42PFL6008H, 42PFL6008K, 42PFL6008S, 42PFL6158K, 42PFL6158S, 42PFL6188K, 42PFL6188S, 42PFL6198K, 42PFL6678K, 42PFL6678S, 42PFL7008H, 42PFL7008K, 42PFL7008S, 42PFL7008T, 42PFL7108H, 42PFL7108K, 42PFL7108S, 42PFL7108T 46PDL8908S, 46PFL8008K
47PFL6008H, 47PFL6008K, 47PFL6008S, 47PFL6158K, 47PFL6158S, 47PFL6188K, 47PFL6188S, 47PFL6198K, 47PFL6678K, 47PFL6678S, 47PFL7008H, 47PFL7008K, 47PFL7008S, 47PFL7108H, 47PFL7108K, 47PFL7108S
55PDL8908D, 55PDL8908S, 55PDL8908S, 55PFL6008H, 55PFL6008K, 55PFL6008S, 55PFL6008T, 55PFL6158K, 55PFL6158S, 55PFL6188K, 55PFL6188S, 55PFL6198K, 55PFL6678K, 55PFL6678S, 55PFL7008H, 55PFL7008K, 55PFL7008S, 55PFL7108H, 55PFL7108K, 55PFL7108S, 55PFL8008K, 55PFL8008S
60PFL6008H, 60PFL6008K, 60PFL6008S, 60PFL8708S
65PFL9708S
84PFL9708, 84PFL9708S


 The appearance of MainBoard 310431366185 is shown in the figure below:
310431366185
The weak point in the PHILIPS TV models assembled on the QFU1.2E LA chassis is the main board SSB (MainBoard), which usually refuses to work after two years of operation. Replacement required.
The cost of the board is quite high, which sometimes raises the question of the feasibility of repairs.
Despite the efforts of designers to complicate or exclude the possibility of repairing the board, there are still options for its restoration.
Attention to the masters !!! You should pay attention to the drop of compound from the bottom of the board. When trying to heat the board or reball of BGA chips, the compound must be completely removed. Otherwise, the paths will be closed, which will significantly complicate the further repair of the board.



310431366185 can be used in TVs:
PHILIPS 42PFL7008S/60 (Panel LC420EUF (AF)(F1)), PHILIPS 40PFL8008S/60 (Panel LTA400HL18 002), PHILIPS 42PFL6008S/60 (Panel LC420EUF (PF)(F1)), PHILIPS 42PFL7108S/60 (Panel LC420EUF PFF1), PHILIPS 47PFL6008S/60 (Panel LC470EUF (PF)(F1) code 430 p/n: 932230114682), PHILIPS 47PFL6008S/60 (Panel LC470EUF (PF)(F1) code 430 p/n: 932230114682), PHILIPS 47PFL7008S/60 (Panel LC470EUF PFF1 code 430 932230114682), PHILIPS 60PFL6008S/60 (Panel LC600EUD FEF2 code 439 p/n: 932230207682), PHILIPS 55PFL8008S/12 (Panel LTA550HQ25), PHILIPS 55PFL7108S/60 (Panel LC550EUF (PF)(F1)), PHILIPS 42PFL6678S/12 (Panel LC420EUF (PF)(F1)).
PSU Advanced
The 42PFL7108S / 60 model uses the FSP140-4FS01 power supply unit using the PFC (Power Factor Correction) node - an active filter of the highest harmonics of the current consumption. In fact, it is a boost converter based on the FAN7930 PWM controller, which eliminates the charge current of the electrolytic capacitor of the rectifier filter directly from the network through open diodes when its charging current is determined by its reactance.
As a result of the operation of the converter, the envelope of the high-frequency pulses of the input current of the converter will repeat the shape and phase of the input voltage. The health of the PFC node can be indirectly judged by the presence of an increased constant voltage (about + 380V) on the capacitor of the rectifier network in operating mode.
The appearance of the power supply
Main features of the PHILIPS 42PFL7108S device:
Installed matrix (LED-panel) LC420EUF PFF1.
The matrix control uses the Timing Controller (T-CON) PH_120PSQBC4LV1.0.
To power the backlight LEDs, a converter is used, combined with the power supply, controlled by the BD9479FV PWM controller.
The necessary supply voltages for all nodes of the PHILIPS 42PFL7108S TV are generated by the FSP140-4FS01 power supply module or its analogs using the FSB117H (Standby 8pin), FAN7930 (PFC), SSC9522S (PWM resonant) microcircuits.
MainBoard - the main board (motherboard) is a module 310431366185, using chips FUSION120, H5TQ2G63BFR, H5TQ2G83BFR and others.
The SUT-RE214AN tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC420EUF-PFF1
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: IPS, Normally Black, Transmissive
Active Area: 927.94x521.96 mm
Surface: Antiglare (Haze 1%), Hard coating (2H)
Brightness: 400 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 16.7M / 1.06B (8-bit / 8-bit + Dithering), CIE1931 72%
Response Time: 5 (G to G); 8 (MPRT)
Frequency: 120Hz
Lamp Type: WLED Without Driver
Signal Interface: LVDS (4 ch, 8/10-bit), 92 pins
Voltage: 12.0V