Monday, 30 March 2020

REPAIR / SERVICING TV TOSHIBA 32WL67R

Technical description and composition of the TOSHIBA 32WL67R TV, type of panel and applicable modules. The composition of the modules.
Toshiba
Model: 32WL67R
Chassis / Version: PE0194
Panel: T315XW02 V.6
Lamp backlight: CCFL
Inverter (backlight): 4H.V1448.291 / B1
PWM Inverter: OZ964SN
MOSFET Inverter: P2804BDG
Power Supply (PSU): PE0197 V28A000177A1 V28A000244A0
PWM Power: STR-Z4567, STR-W676
MainBoard: PE0194 V28A000174A1 & V28A000266B1 PE0203B-1
Tuner: ENG39A16GF
Control: IR: V28A000266B2 PE0203B-2
Specifications 32WL67R
TOSHIBA 32WL67R
General recommendations for repairing TV LCD
Possible malfunctions
- The TOSHIBA 32WL67R TV does not turn on, does not respond to the remote control and the control panel buttons, the indicators do not light or flash.
In some of these cases, a fault is detected in the PE0197 power module. It is necessary to measure its output voltages and, if they are absent, to check the short circuit probability in the converters power switches and rectifier diodes.
In case of diode breakdowns in the secondary circuits, the converter can operate in emergency short-circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM) STR-Z4567, STR-W676, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn on and immediately disappears.
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or the inverter.After checking all the electrolytic capacitors of the filters that are involved in the power supply to the inverter, you must ring in its converter power keys for breakdown and secondary windings of transformers for an open.
Sometimes, for diagnostic purposes, it is necessary to disable the inverter protection. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the PE0194 motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software).
The malfunction of the ENG39A16GF 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.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Entrust repair to professionals with sufficient experience in the field of repair of electronic equipment.



Repair MainBoard
The appearance of MainBoard PE0194 is shown in the figure below:
PE0194
The appearance of the power supply
Main features of the TOSHIBA 32WL67R device:
Installed matrix (LCD panel) T315XW02 V.6.
To power the backlight, an inverter 4H.V1448.291 is used, it is controlled by the PWM controller OZ964SN. As power elements of the inverter, keys of the type P2804BDG are used.
The necessary supply voltages for all nodes of the TOSHIBA 32WL67R TV are generated by the PE0197 power module, or its analogs using the STR-Z4567, STR-W676 microcircuits.
MainBoard - the main board (motherboard) is a PE0194 module.
The ENG39A16GF tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: T315XW02 V6
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: AMVA, Normally Black, Transmissive
Active Area: 697.68x392.26 mm
Surface: Antiglare, Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 6 (G to G)
Frequency: 120Hz (60Hz Input)
Lamp Type: CCFL Embedded (Inverter)
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V

Brand: TOSHIBA, Model: 32WL67R.
Shortly from the TV: LCD, 32 ", 1366x768, 720p HD, sound: 20W, HDMI connectors: 2.
The composition includes MainBoard PE0194 V28A000174A1 & V28A000266B1 PE0203B-1 and LCD-panel T315XW02 V.6.
Power Supply Unit (PSU) PE0197 V28A000177A1 V28A000244A0 Power Supply.
TOSHIBA 32WL67R LCD TV with T315XW02 LCD display, 32 "(81 cm) diagonal size in 16: 9 format. The ratio of maximum brightness to minimum (contrast) is 1000: 1. Dynamic contrast of 3300: 1 is achieved by special control of the backlight. Possible viewing images in high quality HD at a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). The input high-frequency or video signal can be processed in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in the standard tach 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 x2, audio x5, S-Video x2, component x2, VGA, HDMI x2. 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.
The power consumed by the TV in the operating mode from the network is 153 watts.
Overall dimensions: with stand 794x599x298 mm, without stand 794x547x117 mm.
TV Weight: with stand: 20.2 kg, without stand: 17.8 kg.
Attention! The T315XW02 V.6 panel of the TOSHIBA 32WL67R 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!