Technical description and composition of the BBK LT3709S TV, panel type and applicable modules. The composition of the modules.BBK
Model: LT3709S
Chassis / Version: 200-100-GF328-FH
Panel: T370XW01 V.1
T-CON: 05A20-1B T370XW01 V0 CTRL BD
Inverter (backlight): VIT71010.52 (19.26006.141)
PWM Inverter: OZ964SN
MOSFET Inverter: AO4614
Power Supply (PSU): MLT198A REV: 1.4C MLT198A-T1
PWM Power: MC0628R, NCP1653A (PFC), LD7550
MOSFET Power: K3568 9N50 2NK60
MainBoard: 200-100-GF328-FH
IC MainBoard: SPI FLASH: A29040, EEPROM 24C64, SAA7117H, M30620SPGP, SiI9011CLU
Tuner: 200-C00-GF328-DH - JS-6B2 / 121A2 & JS-6B2 / 122-A2.
Technical Specifications LT3709S
BBK LT3709S
General recommendations for repairing TV LCD
Possible manifestations of defects
- BBK LT3709S does not turn on, the indicators on the front panel do not light or flash. The TV does not respond to the control buttons and the remote control.
With such manifestations, a malfunction is most likely to be detected in the MLT198A power supply module. It is then necessary to measure its output voltages and, if they are absent, check the power switches (K3568 9N50 2NK60) and the rectifier diodes of the converters for a short circuit probability.
In case of breakdowns of semiconductors in the secondary circuits, the converter can usually work abnormally in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse often breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM microcircuits MC0628R, NCP1653A (PFC), LD7550 are usually checked by replacing with new ones, or obviously working.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
These manifestations can be triggered by a power module, or by defects in the inverter, as well as a distortion of the currents in the lamps due to their uneven wear. After checking all the electrolytic capacitors of the filters that are involved in the power supply of the inverter, you should ring in its converter the power switches for breakdown and the secondary windings of the transformers for an open.
Sometimes, for diagnostic purposes, inverter protection must be disabled. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the 200-100-GF328-FH motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Checking or replacing SPI FLASH elements: A29040, EEPROM 24C64, SAA7117H, M30620SPGP, SiI9011CLU requires the necessary training and professional skills to repair modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by warming up.
If the TV works normally with external devices, but does not tune into TV channels, the tuner 200-C00-GF328-DH - JS-6B2 / 121A2 & JS-6B2 / 122-A2 may be malfunctioning. In such cases, first of all, make sure the presence of supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Entrust repair to professionals with sufficient experience in the field of repair of electronic equipment.
The appearance of the MainBoard 200-100-GF328-FH is shown in the figure below:200-100-GF328-FH
200-100-GF328-FH can be used in TVs:
BBK LT3709 (Panel T370XW01 rev. 0), BBK LT4005S (Panel LTA400WT-L11).
The appearance of the power supply
Key Features of BBK LT3709S:
Installed matrix (LCD panel) T370XW01 V.1.
The matrix control uses the Timing Controller (T-CON) 05A20-1B.
The VIT71010.52 inverter is used to power the backlight, controlled by the OZ964SN PWM controller. As power elements of the inverter, keys of the type AO4614 are used.
The required supply voltages for all nodes of the BBK LT3709S TV are generated by the MLT198A power module or its analogs using MC0628R, NCP1653A (PFC), LD7550 microcircuits and K3568 9N50 2NK60 type power switches.
MainBoard - the main board (motherboard) is a 200-100-GF328-FH module using SPI FLASH chips: A29040, EEPROM 24C64, SAA7117H, M30620SPGP, SiI9011CLU and others.
Tuner 200-C00-GF328-DH - JS-6B2 / 121A2 & JS-6B2 / 122-A2. provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: T370XW01 V1
Type: a-Si TFT-LCD, Panel
Diagonal size: 37 inch
Resolution: 1366x768, WXGA
Display Mode: AMVA, Normally Black, Transmissive
Active Area: 819.6x460.8 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit)
Response Time: 15/5 (Tr / Td); 8 (G to G)
Frequency: 60Hz
Lamp Type: CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
