Technical description and composition of the PHILIPS 42PFL7674H TV, type of panel and applicable modules. The composition of the modules.PHILIPS
Model: 42PFL7674H / 60
Chassis / Version: Q548.1E LA
Panel: LC420WUF (SB) (N1)
Inverter (backlight): integrated into PSU
PWM Inverter: DAA003A (24pin), DDA002B
Power Supply (PSU): DPS-298CP - 4A
PWM Power: 1606B (PFC), 3BS3LJ (PWM 8pin), DDA005 (6), DDA002B (PWM 20pin),
MainBoard: 3139_123_64423V2 3139 123 64433V2
IC MainBoard: PNX8539EH24182, LAN9420-NU, TDA9996HL / C4
Tuner: HD1816AF / BHXP
Specifications 42PFL7674H
PHILIPS 42PFL7674H
General recommendations for repairing TV LCD
Repair of the PHILIPS TV with the Q548.1E LA chassis should begin with a fault diagnosis, which involves a careful inspection of the external and internal elements of the device. In some cases, visible external damage to the elements can suggest the direction of troubleshooting and localization of the defect even before the start of the necessary measurements at the control points of the nodes of electronic circuits. Ring cracks in the soldering of the leads of the heating elements, swollen electrolytic capacitors, a charred paint layer on the resistors - all this for the repairman can be a significant clue in the assumptions about the causes and consequences of the malfunction.
Malfunctions of the power module can be expressed in different ways, for example, PHILIPS 42PFL7674H does not turn on at all and the control lamps on its front panel do not light up and do not blink, there are no signs of operability. It should be noted that with the same external manifestations, the processor power regulator (converter) may be faulty. Diagnostics and repair of the common power supply should always begin with a check of the mains fuse and the condition of the electrolytic capacitors of the secondary rectifier filters. Defective and swollen capacitors should be replaced with new ones. If the fuse breaks, it is advisable to check for a breakdown, first of all, all the power semiconductor elements of the converter and the diode bridge of the rectifier network, as well as the large electrolytic capacitor of the filter of the rectifier network.
It should be remembered that the keys used in switching power supplies (SMPS) rarely fail without themselves, without any reasons that must be sought by checking other elements of the circuit. Often the breakdown is caused by malfunctions of electrolytic capacitors or semiconductor elements in the primary circuit, or by a break in the resistors in the stabilization circuits. The PWM controller chip can also cause a breakdown of the power switch of the converter.
If the PHILIPS 42PFL7674H does not have an image, but there is sound, there is a possibility of a malfunction of the backlight or power converter. You should also make sure that the electrolytic capacitors of the secondary rectifiers of the common power supply are working. It should be remembered that when protection is disabled in order to diagnose a malfunction, there is always a risk of failure of the power elements of the inverter. After repair, it is necessary to restore all standard converter protection circuits.
We recommend the owners of the 42PFL7674H TV for repair only to qualified specialists with experience! Self-repair attempts without the appropriate knowledge and skills can lead to serious negative consequences!
Service manual and schematic diagram 42PFL7674H/60 Chassis Q548.1E LA
PSU ------------------------> DPS-298CP-2 DELTA schematic diagram
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).
PSU Advanced
The 42PFL7674H / 60 TV is equipped with a DPS-298CP power supply module using the PFC (Power Factor Correction) scheme acting as an active filter to eliminate the higher harmonic components of the current consumption. The step-up converter based on the 1606B PWM controller does not allow the input rectifier filter's electrolytic capacitor to be connected to the network directly through open diodes, when the reactance (about 15-30 ohms at a frequency of 50 Hz) determines the charge current. 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 42PFL7674H device:
Installed matrix (LCD panel) LC420WUF (SB) (N1).
To power the backlight, a converter is used, combined with a power supply, controlled by a PWM controller DAA003A (24pin), DDA002B.
The necessary supply voltages for all nodes of the PHILIPS 42PFL7674H TV are generated by the DPS-298CP power supply module or its analogs using microcircuits 1606B (PFC), 3BS3LJ (PWM 8pin), DDA005 (6), DDA002B (PWM 20pin),.
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 TV 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
