Technical description and composition of the TOSHIBA 42AV633DR TV, type of panel and applicable modules. The composition of the modules.Toshiba
Model: 42AV633DR
Chassis / Version: PE0719
Panel: LC420WUN (SB) (B1) 75014116
T-CON: LC420 / LC470WUN-SBA1 6870C-0243C
Inverter (backlight): PNEL-T805B Rev-0.5
PWM Inverter: BD9215AFV (28)
MOSFET Inverter: IRF248N
Power Supply (PSU): 68-AL43A, SRV2194WW 0245141 75014697
PWM Power: MIP2F2 (Standby), R2A20113SP (PFC), SSC9500 (16)
MOSFET Power: K11A55D, K10A50D
MainBoard: PE0719 V28A000938A
IC MainBoard: TAS5705, TMP91FW27UG, BU9409FV, TPS54310
Tuner: ENG37F01KF
Control: CT-90326 75014827
Appearance
TOSHIBA 42AV633DR
General recommendations for repairing TV LCD
TOSHIBA 42AV633DR TV, like any other, it is advisable to start repairing it by inspecting the internal and external visible physical visual changes. Often, for certain external signs, the repairman can draw some conclusions about the reasons for the failure of certain elements of the circuit even before the necessary measurements are made, which will determine the further algorithm for troubleshooting and localizing the defect. In some cases, faulty elements can be seen with the naked eye, for example, charred resistors or swollen metal-ceramic capacitors, or electrolytic in rectifier filters. Ring cracks formed in the soldered terminals of transformers or heating elements of the circuit are also frequent sources of many malfunctions with a variety of external manifestations.
In the case when the 42AV633DR does not turn on, does not respond to the remote control and the front panel buttons, does not blink bulbs and does not show any signs of operability, most likely the SRV2194WW power supply module is faulty in this case. When diagnosing and repairing the power supply, first of all, it is necessary to check the fuse and, if it is broken, it is necessary to identify the cause. Often in such cases, an avalanche (thermal) breakdown is detected in the power semiconductor elements of the module - rectifier diodes or power key.
As a rule, the keys of flyback converters, which use the N-Fet field effect transistor on a separate radiator, or integrated with the SSC9500 PWM controller in a single chip, are reliable enough and rarely fail for no reason. The reasons for the breakdown of the key should be sought by checking other components of the circuit - electrolytic capacitors, resistors and semiconductor elements of the primary circuit. The PWM chip is verified by replacing it with a known good one.
When using a power factor correction unit (PFC) in the power modules, troubleshooting becomes somewhat more complicated and requires additional experience and knowledge of their operation.
If the TOSHIBA 42AV633DR has no image, but there is sound and the TV is controlled by the remote control, a malfunction in the display backlight nodes is likely. The lamps or the power converter - inverter may be faulty. Often in such cases, when you turn on the TV, an image appears and immediately disappears. First of all, it is necessary to verify the operability of the electrolytic capacitors of the rectifier filter supplying the inverter, and check the LCD lamps by connecting external and obviously serviceable for diagnosis to the connectors.
In most cases, the diagnosis and repair of the T-805BBD9215NF inverter is difficult due to the organization of protection, which turns it off in emergency cases to avoid fires during short circuits or open circuits 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.
In these cases, special care must be taken in view of the risk of failure of the power elements. After completing all repair work, it is imperative to restore the protection circuits for full and safe further operation of the TV by the user.
It should be remembered! Attempts to repair the TOSHIBA 42AV633DR 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!
Toshiba - 32/37/42RV633/635DR Main PE0719 schematic diagram
The appearance of MainBoard PE0719 is shown in the figure below:PE0719
PE0719 can be used in TVs:
TOSHIBA 32AV635DR (Panel LC320WXN (SB)(B1)), TOSHIBA 32RV633DR (Panel LTA320HA04), TOSHIBA 32RV635DR (Panel LTA320HA04), TOSHIBA 42AV633DR (Panel LC420WUN (SB)(B1) 75014116), TOSHIBA 42AV635DR (Panel LC420WUN-SBB1 LC420WUN-SBB1 75014116), TOSHIBA 42RV635D (Panel LC420WUN (SB)(G1)).
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the 68-AL43A module provides for the use of a Power Factor Correction unit. The PFC circuit is a flyback converter based on the R2A20113SP 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
Main features of the TOSHIBA 42AV633DR device:
Installed matrix (LCD panel) LC420WUN (SB) (B1) 75014116.
The matrix control uses the Timing Controller (T-CON) LC420.
The PNEL-T805B inverter is used to power the backlight lamps; it is controlled by the BD9215AFV PWM controller (28). As power elements of the inverter, keys of the type IRF248N are used.
The necessary supply voltages for all nodes of the TOSHIBA 42AV633DR TV are generated by the 68-AL43A power module or its analogs using MIP2F2 (Standby), R2A20113SP (PFC), SSC9500 (16) microcircuits and power switches of the K11A55D, K10A50D type.
MainBoard - the main board (motherboard) is a PE0719 module, using TAS5705, TMP91FW27UG, BU9409FV, TPS54310 and other chips.
The ENG37F01KF tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC420WUN-SBB1
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 930.24x523.26 mm
Surface: Antiglare (Haze 10%), Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 16.7M / 1.06B (8-bit / 8-bit + Dithering)
Response Time: 6 (G to G)
Frequency: 60Hz
Lamp Type: EEFL Embedded (Inverter)
Signal Interface: LVDS (2 ch, 8/10-bit), 51 pins
Voltage: 12.0V