Tuesday, 31 March 2020

REPAIR / SERVICING TV TOSHIBA 42XV550PR

Technical description and composition of the TOSHIBA 42XV550PR TV, type of panel and applicable modules. The composition of the modules.
Toshiba
Model: 42XV550PR
Panel: LC420WUN (SA) (A1)
T-CON: 6870C-4200C
Inverter (backlight): 6632L-0481A - LC420WU - PPW-EE42VF-0 Rev1.6
PWM Inverter: OZ9966SN
MOSFET Inverter: FDB8447L
Power Supply (PSU): 68-FB44A - SRV2170WW + Sub Power PE0397A - V28A00049001
PWM Power: PWM
MainBoard: PE0532 - V28A000710B1
IC MainBoard: FLI32652H, CXB1444R, STA333W, 0747EFI T5CB5-6UK1 F1789ZAE
Tuner: ENG37E11GF
Control: IR: V28A00071302 (PE0534)
Specifications 42XV550PR
TOSHIBA 42XV550PR
General recommendations for repairing TV LCD
Repair of electronic devices, including the TOSHIBA 42XV550PR TV, it is advisable to start with an external examination of its external and internal elements. Specific external damage to some elements can sometimes indicate further actions to determine the malfunction of the TV and localize the defect before the necessary measurements are taken. Experienced repairmen are often aware of the causes of the defect and 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 signs of certain malfunctions.
Malfunctions of the 68-FB44A-SRV2170WW + Sub Power PE0397A-V28A00049001 power supply module can be expressed in different ways, for example, the TOSHIBA 42XV550PR does not turn on at all and the control lights on its front panel do not light up and do not blink, and there are no signs of operability. When repairing the power supply, it is advisable to start the diagnostics by checking the mains fuse and the electrolytic capacitors of the filters of the converter secondary rectifiers. In the event of a fuse breaking, the reason should be sought in the power semiconductor elements of the pulse converter of the main power supply. First of all, it is necessary to check the diodes of the rectifier bridge of the mains voltage and the power key (s) of the converter. The complete inoperability of the power supply unit can be caused by a short circuit in the power elements in the primary circuit, followed by an open fuse, or a short circuit in the loads.
If a breakdown of the power switch is detected, it should be remembered that in a switching power supply (IIP) it does not fail by itself without any reasons that should be sought by checking other elements of the primary circuit - electrolytic capacitors, PWM PWM controller, which can be checked only by replacement, as well as other semiconductor elements (diodes, transistors, zener diodes).
If there is no image when you turn on the TOSHIBA 42XV550PR, or it appears for a second and disappears completely, but there is sound, most likely either the backlight or their power converter (inverter) are faulty. It is necessary to check the electrolytic capacitors of the filter of the secondary rectifiers in the general power supply unit. When disabling the inverter protection (to enable diagnostics), 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.
The motherboard PE0532 - V28A000710B1 must be checked if there is no reaction to the remote control and function buttons, the standby indicator blinks or lights up continuously. In such cases, if the converters or power regulators of the microcircuit are working, a software update may be necessary. Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Testing or replacing elements FLI32652H, CXB1444R, STA333W, 0747EFI T5CB5-6UK1 F1789ZAE requires the necessary training and professional skills to repair modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by warming up.
The malfunction of the ENG37E11GF tuner is established after checking the software and all the supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be controlled by an oscilloscope.
Attention to the owners! Attempts to self-repair the TOSHIBA 42XV550PR TV are not recommended by the manufacturer and can lead to serious negative consequences!





The appearance of MainBoard PE0532 is shown in the figure below:
PE0532
PE0532 can be used in TVs:
TOSHIBA 32CV500PR (Panel LTA320AA03), TOSHIBA 37CV500PR (Panel LC370WXN-SAC1 75011157), TOSHIBA 42CV500PR (Panel LC420WXN-SAB1 75011173), TOSHIBA 42XV550PR (Panel LC420WUN (SA)(A1)), TOSHIBA 32XV550PR (Panel LTA320HA02), TOSHIBA 32XV500PR (Panel LTA320HA02), TOSHIBA 37XV501PR (Panel LC370WUN (SA)(B1)).
The appearance of the power supply
Key Features of the TOSHIBA 42XV550PR:
Installed matrix (LCD panel) LC420WUN (SA) (A1).
The matrix control uses the Timing Controller (T-CON) 6870C-4200C.
To power the backlight, an inverter 6632L-0481A is used, it is controlled by the OZ9966SN PWM controller. As power elements of the inverter, keys of the FDB8447L type are used.
The necessary supply voltages for all nodes of the TOSHIBA 42XV550PR TV are generated by the 68-FB44A power module, or its analogs using PWM chips.
MainBoard - the main board (motherboard) is a PE0532 module, using chips FLI32652H, CXB1444R, STA333W, 0747EFI T5CB5-6UK1 F1789ZAE and others.
The ENG37E11GF tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG.Philips LCD
Model: LC420WUN-SAA1
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 13%), Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 1300: 1
Display Colors: 16.7M / 1.06B (8-bit / 8-bit + Dithering), CIE1931 72%
Response Time: 5 (G to G)
Frequency: 60Hz
Lamp Type: EEFL Embedded (Inverter)
Signal Interface: LVDS (2 ch, 8/10-bit), 51 pins
Voltage: 12.0V
Trademark: TOSHIBA, Model: 42XV550PR.
Short from TV: LCD, 42 ", 1920x1080, 1080p Full HD, sound: 20W, HDMI: 3.
The composition uses MainBoard PE0532 - V28A000710B1 and LCD panel (matrix) LC420WUN (SA) (A1).
Power supply unit (PSU) 68-FB44A - SRV2170WW & Sub Power ЮPE0397A - V28A00049001.
TOSHIBA 42XV550PR LCD TV with LC420WUN LCD, 42 "(106 cm) diagonal display in 16: 9 format. 500 cd / m² screen brightness is provided by CCFL (EEFL) fluorescent lamps. The ratio of maximum brightness to minimum (contrast) is 1300: 1 Dynamic contrast ratio of 25000: 1 is achieved by special control of the backlight operation.The design and technical capabilities of the TV provide for viewing broadcasts and films in high quality HD at a resolution of 1920x1080 pixels in the graphic resolution of the standard 1080p (Full HD). -frequency or video signal can be processed in the analog PAL, SECAM system, NTSC. Graphic processing and formation takes place in the digital signal standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p.
The power of the acoustic system of sound 20 W (2x10 W) provide 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 x3. 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, 1920x1080.
The power consumed by the TV in the operating mode from the network is 207 watts.
Overall dimensions: with stand 1009x694x308 mm, without stand 1009x649x94 mm.
TV Weight: with stand: 23.25 kg, without stand: 19.3 kg.
Attention! The LC420WUN (SA) (A1) panel of the TOSHIBA 42XV550PR LCD TV is its most expensive component.
Avoid hitting the glass and exerting pressure on the screen to avoid permanent damage to the LCD panel!