Technical description and composition of the TOSHIBA 40BV701B TV, type of panel and applicable modules. The composition of the modules.Toshiba
Model: 40BV701B
Chassis / Version: 17MB65-1v.1 VESTEL
Panel: LTA400HM07
MainBoard: 17MB65-1 v. 1
IC MainBoard: MSD9WB7PX-2-Z1, MX25L8005, W971GG6JB-25, NTP-8030,
Tuner: XC5200C
Appearance
TOSHIBA 40BV701B
General recommendations for repairing TV LCD
Repair of the TOSHIBA 40BV701B must begin with the diagnosis of the malfunction and a thorough inspection of its external and internal components, including the case ones. Sometimes, only by some signs can we determine the further direction of the localization of the fault. Experienced repairmen are often aware of the causes of the defect and the possible consequences, for example, from ring cracks in the soldering of the leads of the elements, as well as from swollen capacitors or resistors burnt to coal dust and other external indirect signs.
In the event of a power supply module malfunction, external manifestations may be different, for example, the TOSHIBA 40BV701B does not turn on at all and there is no indication of the indicator lights on the front panel. If the mains fuse is broken in the power supply, in most cases a breakdown of the power switch is detected, which can be integrated with the PWM controller, or a separate field-effect transistor can be used. The rectifier bridge diodes and the electrolytic capacitor of the mains rectifier filter should also be checked.
Power switches in flyback converters fail extremely rarely for no reason and, if they are broken, it is necessary to look for a malfunction in the stabilization circuits by checking electrolytic capacitors, semiconductor devices, and resistors in the primary circuit. The cause may be a malfunction of the PWM controller chip, which can only be checked by replacing it with a new or obviously working one.
If an active Power Factor Corrector (PFC) is used in the power module circuitry, it is sometimes more difficult to troubleshoot. Knowledge, experience, intuition and skills in such cases have a great advantage for a successful repair.
If the TOSHIBA 40BV701B TV does not have an image, but there is sound, the malfunction should be sought in the backlight lamp power converter (inverter). It is also necessary to check the serviceability of the electrolytic capacitors of the filter of the secondary rectifiers of the PSU (power supply) for an overstated ESR.
In most cases, the diagnosis and repair of the inverter is difficult due to the organization of protection, which turns it off in emergency cases in order to avoid fires during short circuits or breaks in high voltage circuits and during depressurization of lamps. Often, repairmen block the protection circuits in order to make the necessary measurements at the control points of the inverter to identify the causes of the defect.
It should be remembered that when the protection is turned off, there is always a risk of failure of the power elements of the inverter during diagnosis. After repair, it is necessary to restore all standard converter protection circuits.
On the 17MB65-1v.1 motherboard, in case of a malfunction, you should first check the performance of all power supply stabilizers of the microcircuits and, if necessary, update the software (software). In cases of attempts to repair the MB (SSB) board, it is necessary to check the serviceability of its elements - MSD9WB7PX-2-Z1, MX25L8005, W971GG6JB-25, NTP-8030, which may require replacement with new ones.
If the TV works properly from external devices but does not tune into television channels, the tuner XC5200C may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals, as well as the power supply of varicaps (30-33V).
It should be remembered! Attempts to repair the TOSHIBA 40BV701B TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> Toshiba Main 17MB65 VESTEL
The appearance of the MainBoard 17MB65-1 is shown in the figure below:17MB65-1
Main features of the TOSHIBA 40BV701B device:
Installed matrix (LCD-panel) LTA400HM07.
The required supply voltage for all nodes of the TOSHIBA 40BV701B TV is provided by a switching power supply.
MainBoard - the main board (motherboard) is a 17MB65-1 module, using microchips MSD9WB7PX-2-Z1, MX25L8005, W971GG6JB-25, NTP-8030, and others.
The XC5200C tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTA400HM07
Type: a-Si TFT-LCD, Panel
Diagonal size: 40 inch
Resolution: 1920x1080, FHD
Display Mode: S-PVA, Normally Black, Transmissive
Active Area: 885.6x498.15 mm
Surface: Antiglare
Brightness: 400 cd / m²
Contrast Ratio: 4000: 1
Display Colors: 16.7M (8-bit), CIE1931 70%
Response Time: 8 (G to G)
Frequency: 60Hz
Lamp Type: 12 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V