Technical description and composition of the ROLSEN RL-20D20 TV, panel type and modules used. The composition of the modules.ROLSEN
Model: RL-20D20
Chassis / Version: PLVM01
Panel: 20 inch
MainBoard: PLVM01
IC MainBoard: VCT49X3R, MLT015GF, A29040BL, TDA7266
Tuner: TECH2949PS40A
RL-20D20 Specifications
ROLSEN RL-20D20
General recommendations for TV LCD repair
It is advisable to start repairing a ROLSEN TV with a TV-DVD chassis with a careful external examination of both internal and external elements. In some cases, visible external damage to elements can suggest directions for troubleshooting and localizing a defect even before the necessary measurements are taken at the control points of electronic circuit assemblies. Experienced repairmen often guess about the causes of the defect and the possible consequences, for example, by ring cracks in the soldering of the element terminals, as well as by swollen capacitors or resistors burnt out to coal dust and other external indirect signs.
In the case when the RL-20D20 does not turn on, does not respond to the remote control and front panel buttons, does not blink light bulbs and does not show any signs of operability, the power module is probably faulty in this case. If it is working properly with such manifestations, it is necessary to check the processor power regulator (converter) on the motherboard.In general, first of all, it is necessary to check the electrolytic capacitors of the secondary rectifier filters and the fuse at the mains input. If it is cut off, then the diodes of the rectifier bridge and the key transistor of the converter, which can be located either on a separate heatsink or integrated with a PWM controller into a common microcircuit, should be checked for a breakdown of PN junctions. Options are possible.
The reasons for the breakdown of the power switch in switching power supplies (SMPS) can be different, for example, a malfunction of semiconductor elements or electrolytic capacitors in the stabilization circuits of the primary circuit, as well as a failure in the operation of a PWM regulator microcircuit or breaks in resistors in its strapping.
If, when you turn on the TV, the image appears and immediately disappears, or is absent initially when turned on, but there is sound and other functions work, there is a high probability of a malfunction of the inverter (backlight power converter). In such cases, the lamps, the inverter and the common power supply module must be checked, in which the electrolytic capacitors of the rectifier filter supplying the inverter must be checked. When disabling the protection of the inverter (to enable diagnostics), special care must be taken due to the risk of failure of the power elements. After the completion of all repair work, it is imperative to restore the protection circuits for the full and safe further operation of the TV by the user.
Complicated MB (SSB) repair is possible only in the conditions of a service center with the necessary equipment. Checking or replacing CPU elements: TW8801, Sound: STV8216, TDA8266D requires the necessary training and professional skills in repairing modules at the component level. Problems associated with BGA soldering technologies can be diagnosed by the warm-up method.
Remember! Attempts of self-repair by users of the ROLSEN RL-20D20 TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> ROLSEN RL-20D20
The appearance of the MainBoard PLVM01 is shown in the figure below:PLVM01
The main features of the ROLSEN RL-20D20 device:
Installed matrix (LCD-panel) 20 inches.
The necessary supply voltages for all nodes of the ROLSEN RL-20D20 TV are provided by a switching power supply.See voltages in picture.
MainBoard - the main board (motherboard) is a PLVM01 module, using VCT49X3R, MLT015GF, A29040BL, TDA7266 and others.
Tuner TECH2949PS40A provides reception of TV programs and tuning to channels.
ROLSEN RL-20D20 LCD TV with 20 "diagonal 4: 3 format. Screen brightness of 500 cd / m² is provided by CCFL (EEFL) fluorescent lamps. Contrast, as the ratio of maximum brightness to minimum, is 500: 1. The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC.Graphic processing and digital signal shaping takes place in the 480i, 480p, 576i, 576p standards.
Speaker power of 6 W (2 x 3 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, S-Video, SCART x2, RGB, VGA. A headphone output is provided. To connect a computer or laptop to this TV model, use the VGA (D-Sub 15) connector on the TV case, this interface supports resolutions: 640x480.
The power consumed by the TV in operating mode from the network is 60 watts.
Dimensions: with stand 510x480x240 mm, without stand 510x435x86 mm.
TV weight: 8.5 kg.
Attention! The ROLSEN RL-20D20 LCD TV panel is its most expensive component.
Avoid hitting the glass and putting pressure on the screen surface to avoid irreversible damage to the LCD panel!