Tuesday, 31 March 2020

REPAIR / SERVICING TV TOSHIBA 42RV635D

Technical description and composition of the TOSHIBA 42RV635D TV, type of panel and applicable modules. The composition of the modules.
Toshiba
Model: 42RV635D
Panel: LC420WUN (SB) (G1)
T-CON: 6871L-1608A 6870C-0243C 1608A
Inverter (backlight): 6632L-0557A PNEL-T810A, Rev-0.6, 2300KTG012C-F
Power Supply (PSU): SRV2169WW - TYPE-2 - 68-FB43B
PWM Power: MIP2F2 (Standby), SSC9500, 8105QL, FA5501A (PFC)
MainBoard: PE0719 V28A000938A1
IC MainBoard: TAS5705PAPR, PCM1754DBQR, TMP91FW27UG (JZ)
Tuner: ENG37F01KF
Control: CT-90326 TV
Specifications 42RV635D
TOSHIBA 42RV635D
General recommendations for repairing TV LCD
It is advisable to start the diagnosis of a malfunction of the TOSHIBA 42RV635D TV, like all others, with an external examination of possible changes, both external and internal elements. Often, by the external signs and nature of some damage, it is possible to draw preliminary conclusions and determine a further algorithm for troubleshooting. Elements with visible damage, for example, capacitors swelled up after boiling the electrolyte, charred resistors in certain nodes of the circuit, as well as ring cracks in solders will help the master to guess the causes and possible consequences of the malfunction.
In the absence of any signs of operability, when the TOSHIBA 42RV635D does not turn on and does not signal anything with the control lights on the panel, the power supply module SRV2169WW, TYPE-2, 68-FB43B is most likely to be faulty. The diagnostics of the power supply should always be started by checking the fuse and, if it is broken, it is first necessary to check the rectifier bridge diodes and the power switch for the likelihood of an avalanche or thermal breakdown.
It should be remembered that the N-FET keys used in flyback converters rarely fail for no reason that must be sought by checking other elements of the circuit. Often the breakdown is caused by malfunctions of electrolytic capacitors or semiconductor elements in the primary circuit, or by a break in the resistors in the stabilization circuits. The PWM controller chip MIP2F2, SSC9500, 8105QL, 5501 may also cause a breakdown of the power switch of the converter.
In cases where the Power Factor Corrector (PFC) is used in the power supply, troubleshooting can be a bit more complicated.
If the TOSHIBA 42RV635D TV does not have an image, but there is sound, the malfunction should be sought in the power converter of the backlight (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.
Diagnosis and repair of the inverter is often complicated by the organization of special protection circuits, which is necessary for fire safety and turns off the inverter in any emergency situation, for example, when the lamps are worn or depressurized. Often, to localize a defect, its blocking is required.
Turning off the protection for diagnostic purposes, it must be remembered that in this case there is a risk of failure of the power elements of the inverter. Upon completion of the diagnosis, all regular protection circuits should be restored.
Diagnosis and repair of the motherboard V28A000938A1, PE0719 is carried out by checking the performance of power stabilizers or updating the software (software).
Before replacing the ENG37F01KF tuner, if there is no tuning to the channels, you must first check the supply voltage at its terminals, including the varicap supply (30-33V).
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repair only to professionals with sufficient experience in the field of electronic equipment repair.

SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------> 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
The SRV2169WW power module is designed using a Power Factor Correction (PFC) scheme to eliminate multiple AC harmonics introduced into the power supply by the device. The PFC node is a Step-Up Converter based on a 5501 PWM controller that evenly distributes high-frequency pulses of the charging current of the electrolytic capacitor of the rectifier filter of the mains voltage over a period of 50 Hz. The current of its charge in this case will already be determined not by its reactance (usually 10-30 ohms for the network frequency), but by the elements of the converter. As a result, a change in the amplitude of the pulses (envelope) of the consumed current of the converter will repeat the shape and phase of the input sinusoidal voltage. The availability of an increased voltage (about + 380V) in the operating mode on the capacitor of the line filter indicates the serviceability of the PFC node.
The appearance of the power supply
Key Features of the TOSHIBA 42RV635D:
Installed matrix (LCD panel) LC420WUN (SB) (G1).
The matrix control uses the Timing Controller (T-CON) 6871L-1608A.
To power the backlight used inverter 6632L-0557A.
The necessary supply voltages for all nodes of the TOSHIBA 42RV635D TV are generated by the SRV2169WW power module or its analogs using MIP2F2 (Standby), SSC9500, 8105QL, FA5501A (PFC) microcircuits.
MainBoard - the main board (motherboard) is a PE0719 module, using TAS5705PAPR, PCM1754DBQR, TMP91FW27UG (JZ) and others.
The ENG37F01KF tuner provides TV reception and channel tuning.
Information from an alternative source:
TOSHIBA 42RV635D
Panel Type (Matrix): LC420WUN (SB) (G1)
Motherboard: V28A000938A1, PE0719, Tuner: ENG37F01KF
T-con: 6871L-1608A 6870C-0243C 1608A
Invertor: 6632L-0557A PNEL-T810A, Rev-0.6, 2300KTG012C-F
PSU: SRV2169WW, TYPE-2, 68-FB43B, MIP2F2, SSC9500, 8105QL, 5501
Remote control: CT-90326 TV

 Brand: TOSHIBA, Model: 42RV635D.
Short from TV: LCD, 42 ", 1920x1080, 1080p Full HD, sound: 20W, HDMI: 4.
For the 42RV635D model, the official website has firmware (software update) version 2.1.77.2.
The composition includes MainBoard PE0719 V28A000938A1 and LCD panel (matrix) LC420WUN (SB) (G1).
Power Supply Unit (PSU) SRV2169WW TYPE-2 68-FB43B Power Supply.
TOSHIBA 42RV635D LCD TV with LC420WUN LCD, 42 "(106 cm) diagonal display in 16: 9 format. The brightness of the screen is 450 cd / m² by CCFL (EEFL) fluorescent lamps. The ratio of maximum brightness to minimum (contrast) is 1300: 1 Dynamic contrast ratio of 50,000: 1 is achieved by special control of the backlight operation.The design and technical capabilities of the TV provide for watching broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in a graphical decomposition according to the standard 1080p (Full HD). the signal can be processed in analogue systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Supported media file formats: JPEG.
The power of the sound system 20 W (2x10 W) provides two speakers. It uses a NICAM stereo signal processing system and Sound Surround.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x3, S-Video, component, SCART x2, RGB, VGA, HDMI x4, USB. An output for connecting headphones is provided. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector is used on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768.
A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C standards.
The power consumed by the TV in the operating mode from the network is 144 watts.
Overall dimensions: with stand 1009x694x308 mm, without stand 1009x649x94 mm.
TV Weight: with stand: 23.5 kg, without stand: 19.7 kg.
Attention! The TOSHIBA 42RV635D's LCD panel LC420WUN (SB) (G1) is the most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!