Saturday, 4 July 2020

REPAIR / SERVICING TV FUSION FLTV-28T20

Technical description and composition of the FUSION FLTV-28T20 TV, panel type and applicable modules. The composition of the modules.
FUSION LED
Model: FLTV-28T20
Chassis / Version: V1M11
Panel: LCM-SM275TK301 (D0306)
T-CON: MT3151A05-1-XC-7
LED driver (backlight): integrated into PSU
PWM LED driver: OB3350CP
Power Supply (PSU): CVB32005
PWM Power: AP3105NV (PWM SOT23-6)
Mainboard: CV9202H-TPW
IC MainBoard: SPI FLASH: 25Q64
Tuner: ST03WS-2A-E
Technical Specifications FLTV-28T20
FUSION FLTV-28T20
General repair guidelines for TV LCD LED
Repair of the FUSION FLTV-28T20 TV should begin with a fault diagnosis, which involves a careful examination 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. In most cases, the repairman can guess the causes of the defect and possible consequences by the characteristic signs of typical TV defects, for example, ring cracks formed in the soldering of the element leads, swollen rectifier filter capacitors, charred resistors and other circuit elements.
In the case when the FLTV-28T20 does not turn on, does not respond to the remote control and buttons on the front panel, does not blink bulbs and does not show any signs of operability, the power supply module is probably defective in this case. If it is serviceable under such manifestations, it is necessary to check the power supply stabilizer (converter) of the processor on the motherboard.When diagnosing and repairing the power supply, after replacing the swollen capacitors of the secondary rectifier filters (if any), it is necessary first of all to check the mains fuse. When it is broken, the power elements of the transistors and diodes of the rectifier bridge should be checked for avalanche (thermal) breakdown.
It should be remembered that in the practice of repair, usually the power switches in switching power supplies (SMPS) do not fail due to their poor quality and, in such cases, it is necessary to look for the cause that led to a malfunction and provoked a breakdown of the key. Most often, the culprits of the accident are dried electrolytic capacitors or dangling resistors in the primary circuit, or the PWM controller chip itself may be faulty. It is also necessary to check all the semiconductor elements of the stabilization circuit in the primary and secondary circuits.
If there is no image when you turn on the FUSION FLTV-28T20, or it appears for a second and disappears, but there is sound, most likely there is a malfunction in the backlight LED circuit of the LCM-SM275TK301 D0306 panel, or in their power converter. It is necessary to check the electrolytic capacitors of the filter of the secondary rectifiers in the general power supply unit.
In most cases of lack of backlight, there is a need to disassemble the panel in order to check the LEDs, connectors, loops and all contact connections. If one or several LEDs does not work in one line, therefore, they are broken and should be replaced.
To check the LED lines for breaks without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter, a voltage of the order of several tens of volts is required.
If the motherboard CV9202H-TPW is faulty, first of all it is necessary to check all the linear stabilizers or power converters of its chips, and also, if necessary, update the software. Sometimes you can check the health of MB only by replacement.
In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its SPI FLASH: 25Q64 chips and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by heating.
Attention! For users and owners of FLTV-28T20 TVs who do not have the appropriate qualifications, knowledge and experience, we strongly recommend against attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.

FIRMWARE FOR SPI FLASH  ----------->   FUSION FLTV-28T20 V1M11, Main: CV9202H-TPW, Panel: LCM-SM275TK301 D0306

 In case of failures in the software of Winbond SPI FLASH microcircuits, they can for some time restore their performance after temperature exposure - heating the soldering station with a hairdryer or even a lighter. Usually this is enough to read the regular contents of the software. In such cases, the chip must be replaced with a new one.

Repair MainBoard
The appearance of the MainBoard CV9202H-TPW is shown in the figure below:
CV9202H-TPW
CV9202H-TPW can be used in TVs:
AKAI LEA-39J29P (Panel HF390BGA-C1), BBK 32LEM-1001/T2C (Panel CX315DLEDM), DNS M39DM8 (Panel V390HJ1-P02 Rev C1), ERISSON 32LEE17 (Panel 720p HD 1366x768), FUSION FLTV-32T22 (Panel ST3151A05), FUSION FLTV-28T20 (Panel LCM-SM275TK301 (D0306)), FUSION FLTV-28T22 (Panel TH280L321-04), FUSION FLTV-32T23 (Panel ST3151A04-1 / Ver.2.4), FUSION FLTV-32T20 (Panel V320BK1-PS5 Rev.C7), TELEFUNKEN TF-LED40S28T2 (Panel CX400DLEDM), TELEFUNKEN TF-LED29S30T2 (Panel V290BJ1-XC01 CX290DLEDM), TELEFUNKEN TF-LED40S6T2 (Panel CX400DLEDM).
The appearance of the power supply
Main features of the FUSION FLTV-28T20 device:
Installed matrix (LED-panel) LCM-SM275TK301 (D0306).
The matrix control uses the Timing Controller (T-CON) MT3151A05-1-XC-7.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by the OB3350CP PWM controller.
The necessary supply voltages for all nodes of the FUSION FLTV-28T20 TV are generated by the CVB32005 power module or its analogs using AP3105NV microcircuits (PWM SOT23-6).
MainBoard - the main board (motherboard) is a CV9202H-TPW module, using SPI FLASH chipsets: 25Q64 and others.
The ST03WS-2A-E tuner provides reception of television programs and tuning to channels.
FUSION FLTV-28T20 TV with LCD display LCM-SM275TK301, diagonal size 28 "(71 cm) in 16: 9 format. The required brightness of the screen is 320 cd / m² LED backlighting. Dynamic contrast ratio 80000: 1 is achieved by special control of the LEDs The LED-panel of this TV is equipped with LED end-lighting - Edge LED. You can view images in high quality HD at a resolution of 1366x768 pixels in the standard for graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analogue systems PAL, SECAM , NTSC. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i. Supported media file formats: MP3, MKV, JPEG. Stereo sound is realized by two built-in speakers. The audio processing system NICAM STEREO is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF),. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector is used on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768, 1360x768.
Attention! The LCM-SM275TK301 (D0306) panel of the FUSION FLTV-28T20 LED TV is an expensive and unreliable element.
Avoid any impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also unsafe to get liquid on the screen. Sometimes one drop is enough if it flows down the glass onto the cables so that the TV becomes unrepairable.