Technical description and composition of the PHILIPS 42PFL7404H TV, type of panel and applicable modules. The composition of the modules.PHILIPS
Model: 42PFL7404H / 60
Chassis / Version: Q548.1E LA
Panel: LC420WUF (SB) (N1)
Lamp backlight: 18 Lamp CCFL
T-CON: 6870C-4000H (SB) (N1)
Inverter (backlight): integrated into PSU
PWM Inverter: DAA003A, DDA002B
Power Supply (PSU): DPS-298CP -4 A 2722 171 00752 REV: 01 F
PWM Power: 3BS3LJ (PWM 8pin), 1606B (PFC), DDA005 (6), DDA002B (PWM 20 pin)
MOSFET Power: K4101, P6NK60ZFP
MainBoard: 3139_123_64423V2 BD 3139 123 64433V2 (3A) WK928.3
IC MainBoard: PNX8539EH24182, LAN9420-NU, TDA9996HL / C4
Tuner: HD1816AF / BHXP
Control: IR: 2722 171 00726 (GWA7.820.628-4B HT)
Specifications 42PFL7404H
PHILIPS 42PFL7404H
General recommendations for repairing TV LCD
Possible malfunctions
- The PHILIPS 42PFL7404H TV does not turn on, does not respond to the remote control and control panel buttons, does not light up or blink indicators.
Typically, with such manifestations, the defect is caused by faulty elements in the DPS-298CP main power module. It is necessary to verify the presence of its output voltages and, if they are completely absent, check the power switches (K4101, P6NK60ZFP) 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 damping circuits, or negative feedback elements in the stabilization circuit. PWM controllers 3BS3LJ (PWM 8pin), 1606B (PFC), DDA005 (6), DDA002B (PWM 20 pin), 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.
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or the inverter.After checking all the electrolytic capacitors of the filters that are involved in the power supply to the inverter, you must ring in its converter power keys for breakdown and secondary windings of transformers for an open.
Sometimes, for diagnostic purposes, it is necessary to disable the inverter protection. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the 3139_123_64423V2 motherboard should begin by checking the stabilizers and power converters needed to power the microcircuits and matrix. If necessary, update or replace the software (software). When repairing an MB board, you need to check its components PNX8539EH24182, LAN9420-NU, TDA9996HL / C4. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the method of local heating of the chip.
If the TV works normally with external devices, but does not tune into television channels, the HD1816AF / BHXP tuner may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Attention to users! Self-repair of a PHILIPS 42PFL7404H TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
Service manual and schematic diagram -----------------> PHILIPS 42PFL7404H Chassis Q548.1E LA
The appearance of MainBoard 3139_123_64423V2 is shown in the figure below:3139_123_64423V2
3139_123_64423V2 can be used in TVs:
PHILIPS 32PFL7864H/60 (Panel LC320WUF-SBN1), PHILIPS 32PFL8404H/60 (Panel LC320WUF (SB)(N1) code 181 p/n: 932226687682), PHILIPS 37PFL8404H/60 (Panel T370HW03 V.2 code 189), PHILIPS 42PFL7674H/60 (Panel LC420WUF(SB)(N1)), PHILIPS 42PFL7864 (Panel 42 ), PHILIPS 42PFL8404H/60 (Panel LC420WUF-SBN1 code 183 p/n: 932226646682).
The appearance of the power supply
Main features of the PHILIPS 42PFL7404H device:
Installed matrix (LCD panel) LC420WUF (SB) (N1).
The matrix control uses the Timing Controller (T-CON) 6870C-4000H.
To power the backlight, a converter is used, combined with a power supply, controlled by a PWM controller DAA003A, DDA002B.
The necessary supply voltages for all nodes of the PHILIPS 42PFL7404H TV are generated by the DPS-298CP power supply module or its analogs using 3BS3LJ (PWM 8pin), 1606B (PFC), DDA005 (6), DDA002B (PWM 20 pin) microcircuits and power switches of the K4101 type , P6NK60ZFP.
MainBoard - the main board (motherboard) is a module 3139_123_64423V2, using chips PNX8539EH24182, LAN9420-NU, TDA9996HL / C4 and others.
The HD1816AF / BHXP tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC420WUF-SBN1
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 930.24x523.26 mm
Surface: Antiglare (Haze 10%), Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 16.7M / 1.06B (8-bit / 8-bit + Dithering)
Response Time: 5 (G to G); 8 (MPRT)
Frequency: 120Hz
Lamp Type: 18 pcs EEFL Without Driver
Signal Interface: LVDS (4 ch, 8/10-bit), 92 pins
Voltage: 12.0V