Technical description and composition of the PHILIPS 20PF5121 TV, type of panel and applicable modules. The composition of the modules.PHILIPS
Model: 20PF5121 / 58
Chassis / Version: LC4.1E AB
Panel: LC201V02-SDB1 p / n: 6870S-0309B
Inverter (backlight): DAC-12M019 AOF 3139 128 77613
Power Supply (PSU): DAC-12M019
MainBoard: 3139_123_60191
IC MainBoard: CPU: TDA15021H1 / N1C91; Scaler: GM5221H-LF
Tuner: UR1316S / A
Technical Specifications 20PF5121
PHILIPS 20PF5121
General recommendations for repairing TV LCD
Any repair of electronic equipment usually begins with a careful external inspection of the device and troubleshooting. In this case, you should inspect all the elements of the PHILIPS 20PF5121 / 58 TV, both internal and external. Often, according to the external signs and the nature of some damage to the elements, it is possible to draw preliminary conclusions and determine a further algorithm for troubleshooting and localizing the malfunction before carrying out the necessary measurements and taking oscillograms at control points. Carbonized paint on the upper layer of resistors, electrolytic capacitors of rectifier filters swollen after boiling, cracked soldering at the terminals of heating elements or transformers can often suggest the cause of the defect and possible consequences.
In cases when the PHILIPS 20PF5121 / 58 TV does not turn on, does not respond to the remote control and buttons, any indicators on the front panel do not light or blink, and there are no sounds and no signs of operability when turning on, the CA001V L927A2 power supply module is most likely to be faulty or , which happens somewhat less often, - there is no processor power on the motherboard (a typical defect of some PHILIPS TVs). First of all, it is necessary to replace the swollen capacitors of the rectifier filters, if any. If the mains fuse is broken in the power supply, in most cases a breakdown of the power switch is detected, which can be integrated with the PWM controller, or a separate field-effect transistor can be used. The rectifier bridge diodes and the electrolytic capacitor of the mains rectifier filter should also be checked.
It should be borne in mind that in the repair practice it is extremely rare that key transistors of the N-FET type fail for no reason that should be looked for by checking other components, for example, a breakdown of the key can provoke faulty elements of the damper circuits, either dried electrolytic capacitors or dangling resistors of the primary circuit of the PSU, involved in the stabilization process. In this case, all semiconductor elements of the strapping of the PWM controller chip are subject to verification, which it is desirable to verify by replacement.
Diagnostics of power modules with a Power Factor Corrector (CMC) is somewhat more complicated and requires a more detailed approach.
If the PHILIPS 20PF5121 / 58 TV does not have an image, but there is sound, the malfunction should be sought in the power converter of the backlight (inverter). It is also necessary to check the serviceability of the electrolytic capacitors of the filter of the secondary rectifiers of the BP (power supply) for an overstated ESR.
Diagnosis of the inverter DAC-12M019 AOF 3139 128 77613 can be difficult due to the protection being triggered, which is organized by the designers to prevent negative consequences or fires in emergency cases, for example, during short circuits or breaks in the lamp power supply circuit, as well as their possible leakage. To make the necessary measurements at control points or to take the necessary waveforms, repairmen have to block the protection circuits in order to be able to diagnose.
In these cases, special care must be taken in view of the risk of failure of the power elements. After completing all repair work, it is imperative to restore the protection circuits for full and safe further operation of the TV by the user.
Repair of the motherboard must begin with the diagnosis and verification of all linear stabilizers or power converters of its microcircuits. Sometimes it may be necessary to update the software (software) - flashing FLASH or EEPROM.
It should be remembered! Attempts to repair the PHILIPS 20PF5121 / 58 TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!
Service manual and schematic diagram 20PF5121/58 Chassis LC4.1E AB
MODELS: 15PF4110, 15PF5120, 17PF4310, 20PF4110, 20PF4310, 20PF5120, 20PF5320, 23PF5320
The appearance of MainBoard 3139_123_60191 is shown in the figure below:3139_123_60191
3139_123_60191 can be used in TVs:
PHILIPS 15PF4110 (Panel 15 inch), PHILIPS 20PF5121/58 (Panel LC201V02-SDB1 p/n: 6870S-0309B).
The appearance of the power supply
Main features of the PHILIPS 20PF5121 device:
Installed matrix (LCD panel) LC201V02-SDB1 p / n: 6870S-0309B.
To power the backlight used inverter DAC-12M019.
The formation of the necessary supply voltages for all nodes of the PHILIPS 20PF5121 TV is carried out by the DAC-12M019 power module, or its analogues.
MainBoard - the main board (motherboard) is a module 3139_123_60191, using CPU chips: TDA15021H1 / N1C91; Scaler: GM5221H-LF and others.
The tuner UR1316S / A provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG.Philips LCD
Model: LC201V02-SDB1
Type: a-Si TFT-LCD, Panel
Diagonal size: 20.1 inch
Resolution: 640x480, VGA
Display Mode: IPS, Normally Black, Transmissive
Active Area: 408x306 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 450 cd / m²
Contrast Ratio: 800: 1
Display Colors: 16.7M (8-bit)
Response Time: 12/13 (Tr / Td)
Frequency: 60Hz
Lamp Type: 6 pcs CCFL Without Driver
Signal Interface: CMOS (1 ch, 8-bit), 41 pins
Voltage: 12.0V
