Saturday, 29 August 2020

REPAIRING / SERVICING TV RUBIN RB-22SE2FT2S

Technical description and composition of the RUBIN RB-22SE2FT2S TV, panel type and modules used. The composition of the modules.
RUBIN LED
Model: RB-22SE2FT2S
Chassis / Version: CV512L-B
Panel: 1080p Full HD, 1920x1080
LED backlight: EDGE LED
Power Supply (PSU): Adapter 12V
MainBoard: CV512L-B
IC MainBoard: CPU: S2T512, Spi Flash: 25Q64FVSIG
Tuner: T34WN-2T-E (TDA18275), RDA5815
Specifications RB-22SE2FT2S
RUBIN RB-22SE2FT2S
General recommendations for TV LCD LED repair
Repair of the RUBIN RB-22SE2FT2S TV should begin with a malfunction diagnosis, which involves a careful examination of the external and internal elements of the device. It often happens that visible damage to elements or connections helps determine the direction of troubleshooting. Elements with visible damage, for example, capacitors swollen after electrolyte boiling, charred resistors in certain nodes of the circuit, as well as ring cracks in the solders, will help the master guess about the causes and possible consequences of the malfunction.
In the case when the RB-22SE2FT2S does not turn on, does not respond to the remote control and front panel buttons, does not blink lights 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.
Power switches in switching power supplies (SMPS) fail for no reason very rarely and, in case of their breakdown, it is necessary to look for a malfunction in the stabilization circuits, checking electrolytic capacitors, semiconductor devices and resistors in the primary circuit. The reason may be a malfunction of the PWM regulator microcircuit, which can only be checked by replacing it with a new or known good one.
If RUBIN RB-22SE2FT2S does not have an image, there is sound and the channels are switched, there is a possibility of a malfunction in the LED circuit of the 1080p Full HD panel backlight, 1920x1080, or their power converter - LED driver. Sometimes, when turned on, the image appears and disappears immediately. In such cases, it is necessary to check the electrolytic capacitors of the power filter of the LED driver itself, including in the secondary rectifier of the main power supply unit.
A malfunction in the backlight circuits often occurs due to an open circuit in the power supply circuit of the LED lines. It is required to disassemble the panel and check the LEDs themselves, the ration of their conclusions, as well as the reliability of the connections in the connectors and the ration of the connector pins.
When diagnosing, it must be borne in mind that it is impossible to check for an open in the circuit of the LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally a current source.
If the CV512L-B motherboard is faulty, first of all, you need to check all the linear stabilizers or power converters of its chips, and also, if necessary, update the software. Sometimes it is possible to check the health of the MB only by replacing it.
In cases of attempts to repair the MB (SSB) board, it is necessary to check the serviceability of its elements - Spi Flash: 25Q64FVSIG which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its pins with the board (detected by warming up).
If the TV operates normally from external devices, but does not tune to TV channels, the DVB-T2 tuner may be faulty. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals.
Attention! Users and owners of RB-22SE2FT2S TVs who do not have the appropriate qualifications, knowledge and experience are strongly discouraged from attempting to repair themselves in order to avoid negative consequences that can lead to complete non-repairability of the device.


DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    Main CV512L-B 


DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   RUBIN RB-22SE2FT2S, Main: CV512L-B, Panel: 1080p Full HD, 1920x1080


 The external view of the MainBoard CV512L-B is shown in the figure below:
CV512L-B
CV512L-B can be used in TVs:
BBK 28LEM-1021/T2C (Panel SV275SHD HX010403 X41), BBK 22LEM-1026/FT2C (Panel M215HGE-P02), DEXP H24B7100E (Panel CX236LEDM (V236BJ1-P01)), DEXP F22B7000E/B (Panel CX215LEDM), ERISSON 22LEE31T2 (Panel CX215LEDM), RUBIN RB-22SE2FT2S (Panel 1080p Full HD 1920x1080), SUPRA STV-LC24T880WL (Panel HV236WHB-N00), SUPRA STV-LC22T880FL (Panel LC215DTBA).
Key features of the RUBIN RB-22SE2FT2S device:
Installed matrix (LED panel) 1080p Full HD, 1920x1080.
To power all the internal components of the RUBIN RB-22SE2FT2S TV, an external adapter 12V is used.
MainBoard - the main board (motherboard) is a CV512L-B module, using CPU chips: S2T512, Spi Flash: 25Q64FVSIG and others.
Tuner T34WN-2T-E (TDA18275), RDA5815 provides reception of television programs and tuning to channels.
RUBIN RB-22SE2FT2S LCD TV 22 "(56 cm) in 16: 9 format. The required screen brightness of 250 cd / m² is provided by LED backlighting. Dynamic contrast ratio of 170,000: 1 is achieved by a special control of the LEDs. LED backlighting for this TV model is implemented.The design and technical capabilities of the TV provide viewing of broadcasts and films in high quality HD at a resolution of 1920x1080 pixels in graphic resolution according to the standard 1080p (Full HD) .Input high-frequency or video signal can be processed in analog systems PAL , SECAM, NTSC Graphic processing and digital signal shaping is carried out in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p Supported multimedia file formats: MP3, WMA, MPEG4, MKV, JPEG.
Speaker power of 10 W (2x5 W) is provided by two speakers. Uses the NICAM stereo signal processing system and the Sound Surround function.
An external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, SCART, VGA, HDMI, USB. 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, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080.
The digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2, DVB-S2 standards.
Dimensions: with stand 503x327x175 mm, without stand 503x305x51 mm.
TV weight: with stand: 3.9 kg, without stand: 3.3 kg.
Attention! The panel of the RUBIN RB-22SE2FT2S LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.