Technical description and composition of the TOSHIBA 40AV700V TV, type of panel and applicable modules. The composition of the modules.Toshiba
Model: 40AV700V
Chassis / Version: 32AV700
Panel: LTA400HM04
T-CON: A60MB4C2LV0.2
Inverter (backlight): integrated into PSU
PWM Inverter: BD9893F, A393F
MOSFET Inverter: FDPF7N50U
Trans Inverter: LT-TU40
Power Supply (PSU): PSIV231I01T V71A00016600
PWM Power: SEM3040 (PFC), STR-W6052
MOSFET Power: SD10N60 (PFC)
MainBoard: V28A00112301 PE0849
IC MainBoard: MST6B884JL-LF-3, MX25L1605, 24C64. CXB1446AR, HJ50U281622FTP-4
Tuner: TDTC-G432D
Control: IR: V28A00112401
Specifications 40AV700
TOSHIBA 40AV700V
General recommendations for repairing TV LCD
Diagnostics of malfunctions and repairs of the TOSHIBA 40AV700V, as well as other electronic devices, is recommended to begin with an external examination of the external and internal elements. It often happens that visible damage to elements or connections helps determine the direction of the troubleshooting. Useful tips can include swollen capacitors, ring cracks formed in the soldered terminals, a charred paint layer on the resistors, signs of overheating of the board, and many other external signs familiar to experienced repairmen.
In the absence of any signs of operability, when the TOSHIBA 40AV700V does not turn on and does not signal anything with the control lights on the panel, there is a possibility of a malfunction of the PSIV231I01T V71A00016600 TV power supply module. It is advisable to start the troubleshooting of the power supply module by checking the state of the electrolytic capacitors of the rectifier filters and the mains fuse. Defective capacitors should be replaced. If the mains fuse is broken, it is necessary to check first of all the power semiconductor elements - rectifier diodes and transistors, which are often found in such a state of breakdown.
The reasons for the breakdown of the power switch in pulsed power supplies (IIPS) can be different, for example, a malfunction of semiconductor cells or electrolytic capacitors in the stabilization circuits of the primary circuit, as well as a failure in the operation of the PWM controller chip or broken resistors in its bundle.
Sometimes the TOSHIBA 40AV700V TV does not have an image, but there is sound, or the image appears and immediately disappears. In this case, there is a high probability of a malfunction of the backlight converter, or of the lamps themselves, which can be checked by replacement. In such cases, it is necessary to verify the serviceability of all electrolytic capacitors of the filter according to the power supply of the inverter itself, including in the power supply unit (power supply unit). When disabling protection in order to enable the diagnosis of a malfunction, special care should be taken, and after completion of all repair work, it is necessary to restore the circuit and the inverter protection for further safe operation of the TV.
If the motherboard V28A00112301 PE0849 is faulty, first of all it is necessary to check all the linear stabilizers and power converters of its chips, and also, if necessary, update the software (software). Sometimes you can check the health of MB only by replacement. In some cases, it is necessary to check or replace (if necessary) the elements of the MainBoard board - MST6B884JL-LF-3, MX25L1605, 24C64. CXB1446AR, HJ50U281622FTP-4. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
Before changing the tuner TDTC-G432D, if there is no possibility of tuning to television channels, you should make sure that there are supply voltages that must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Attention to users! Self-repair of the TOSHIBA 40AV700V TV without the appropriate qualifications and experience can lead to its complete non-repairability!
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> TOSHIBA 40AV700V Chassis 32AV700.
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> PSIV231I01T V71A00016600 Schematic diagram
The appearance of the MainBoard V28A00112301 is shown in the figure below:V28A00112301
V28A00112301 can be used in TVs:
TOSHIBA 32CV700 (Panel LTA320AP15), TOSHIBA 40AV700V (Panel LTA400HM04).
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the PSIV231I01T module provides for the use of a power factor correction unit (Power Factor Correction). The PFC circuit is a flyback converter based on the SEM3040 PWM controller. The reactance of an electrolytic capacitor of a line filter at a frequency of 50-60 Hz is usually not more than 20-30 ohms and its charge directly from the network through open diodes could reach tens of amperes per pulse if no filtering were applied.
As a result of the PFC conversion, an increased voltage on the capacitor (about 380V) cannot directly open the rectifier diodes, on the anode of which the voltage will always be slightly less (about 300V) and then its charging current will always be limited by the elements of the PWM controller. As a result, the envelope of the high-frequency pulses of the consumed current will repeat the shape and phase of the input sinusoidal voltage. The presence of an increased voltage (+ 380V) on the network capacitor indicates the serviceability of the PFC node.
The appearance of the power supply
Key Features of the TOSHIBA 40AV700V:
Installed matrix (LCD panel) LTA400HM04.
The matrix control uses the Timing Controller (T-CON) A60MB4C2LV0.2.
To power the backlight, a converter is used, combined with a power supply unit, controlled by a BD9893F, A393F PWM controller. A transformer LT-TU40 is installed in the inverter converter. As power elements of the inverter, keys of the FDPF7N50U type are used.
The necessary supply voltages for all nodes of the TOSHIBA 40AV700V TV are generated by the PSIV231I01T power module or its analogs using SEM3040 (PFC), STR-W6052 microchips and SD10N60 (PFC) type power switches.
MainBoard - the main board (motherboard) is a module V28A00112301, using microchips MST6B884JL-LF-3, MX25L1605, 24C64. CXB1446AR, HJ50U281622FTP-4 and others.
The TDTC-G432D tuner provides television reception and channel tuning.