Saturday 21 March 2020

REPAIR / SERVICING TV BBK LT2617S

Technical description and composition of the BBK LT2617S TV, panel type and applicable modules. The composition of the modules.
BBK
Model: LT2617S
Chassis / Version: RSAG7
Panel: V260B1-L02 rev.c1
T-CON: V260B1-P02; AAT1168B, i7724DA X2
Inverter (backlight): integrated into PSU
PWM Inverter: FAN7313
Power Supply (PSU): HLP-20A11 LIPS
PWM Power: FAN7602, FAN7530 (PFC), FAN7382
MainBoard: RSAG7.820.1269 / ROH VER.C
IC MainBoard: MST9E19B-LF, TDA7266SA, CM1671-KQ, A25L40PUO, AZ4558CM, TDA9886TS, P15V330SQE, AP1520
Tuner: TDQ-6FT / W126H / ROH
Technical Specifications LT2617S
BBK LT2617S
General recommendations for repairing TV LCD
Possible manifestations of defects
- BBK LT2617S TV does not turn on, does not respond to the remote control and control panel buttons, indicators do not light up and do not blink.
With such manifestations, the HLP-20A11 power module usually fails. It is necessary to measure its secondary output voltages, and in case of their absence, check the serviceability of the power switches of the converters and rectifier diodes for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during short circuit in the elements of the primary circuit, the mains fuse usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power supply, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. PWM chip FAN7602, FAN7530 (PFC), FAN7382 can also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
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. If all the electrolytic capacitors of the filter according to the inverter power supply are serviceable, you should make sure that the lamps are working, then you need to check the converter keys and the secondary windings of the transformers.
If in diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during work, and after they are finished, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- 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 RSAG7.820.1269 motherboard should begin by checking the stabilizers and power converters needed to power the microcircuit and matrix. If necessary, update or replace the software (software). 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 chips MST9E19B-LF, TDA7266SA, CM1671-KQ, A25L40PUO, AZ4558CM, TDA9886TS, P15V330SQE, AP1520 and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
In the absence of tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltages on the terminals of the tuner TDQ-6FT / W126H / ROH. It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
TV users and owners need to remember that attempts to self-repair a BBK LT2617S TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!


Service Manual with Schematic Diagram 60 pages of 2008 on the LT1921S, LT2621S, LT3221S, LT1919S LT2619S, LT3219S, LT1917S, LT2617S.



The appearance of the MainBoard RSAG7.820.1269 is shown in the figure below:
RSAG7.820.1269
RSAG7.820.1269 can be used in TVs:
BBK LT2617S (Panel V260B1-L02 rev.c1), BBK LT2621S (Panel V260B1-L02), BBK LT3221S (Panel V315B1-L01 Rev.C2), BBK LT3217S (Panel AX080D002F), BBK LT3219S (Panel V315B1-L01 Rev.C2).
PSU Advanced
The LT2617S model uses the HLP-20A11 power supply unit using the PFC (Power Factor Correction) node - an active filter of the highest harmonics of the current consumption. In fact, it is a boost converter based on the FAN7530 PWM controller, which eliminates the charge current of the electrolytic capacitor of the rectifier filter directly from the network through open diodes, when its charging current is determined by its reactance.
As a result of the operation of the converter, the envelope of the high-frequency pulses of the input current of the converter will repeat the shape and phase of the input voltage. The health of the PFC node can be indirectly judged by the presence of an increased constant voltage (about + 380V) on the capacitor of the rectifier network in operating mode.
The appearance of the power supply
Main features of the BBK LT2617S device:
Installed matrix (LCD panel) V260B1-L02 rev.c1.
The matrix control uses the Timing Controller (T-CON) V260B1-P02 ;.
To power the backlight, a converter is used, combined with the power supply, controlled by the FAN7313 PWM controller.
The necessary supply voltages for all nodes of the TV BBK LT2617S are generated by the HLP-20A11 power module, or its analogs using FAN7602, FAN7530 (PFC), FAN7382 microcircuits.
MainBoard - the main board (motherboard) is an RSAG7.820.1269 module, using microchips MST9E19B-LF, TDA7266SA, CM1671-KQ, A25L40PUO, AZ4558CM, TDA9886TS, P15V330SQE, AP1520 and others.
The TDQ-6FT / W126H / ROH tuner provides TV reception and channel tuning.
Information from an alternative source:
BBK LT2617S
Panel Type (Matrix): V260B1-L02 rev.c1
Motherboard:RSAG7.820.1269/ROH VER.C, CM1671A-KQ, A25L40PUO, 24C32AN, 24С08, 24C02, AP1520, TE330, 4558CM х3, TDA9886TS, TDA7266SA, Tuner: TDQ-6FT/W126H\ROH
T-con: V260B1-P02, AAT1168B, i7724DA X2
PSU & Inverter: LIPS HLP-20A11 RSAG7.820.1235/ROH, FAN7382, FAN7530, FAN7602, FAN7313, FQPF7N50U X2, FQPF3N80C, FQPF10N60C ,
Additional technical information about the panel:
Brand: CMO
Model: V260B1-L02
Type: a-Si TFT-LCD, Panel
Diagonal size: 26.0 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 575.769x323.712 mm
Brightness: 450 cd / m²
Contrast Ratio: 800: 1
Display Colors: 16.2M (6-bit + FRC), CIE1931 72%
Response Time: 3/5 (Tr / Td)
Frequency: 60Hz
Lamp Type: 4 pcs CCFL Without Driver
Signal Interface: RSDS (1 Channel), 45 pins
Voltage: 5.3.3 / 5.0V (VDD / VIN5)