TOSHIBA LED
Model: 20VL66R
Panel: A201SN02 V.5
LED driver (backlight): EADP-70AF
Power Supply (PSU): EADP-70AF
MainBoard: 4H.00501 .A00 T20VV8 GA / CN PCBA MAIN BD 75004566 PLOTECH 64W42230 4H.00501.A00
IC MainBoard: CPU: PW106B-10L; AD9381, MSP3410
Tuner: ENG39A11GF
Specifications 20VL66R
TOSHIBA 20VL66R
General repair guidelines for TV LCD LED
Repair of electronic equipment usually begins with its external inspection and diagnosis of the malfunction. In this case, you should examine all the internal components of the TOSHIBA 20VL66R TV, as well as the external elements of the housing. In some cases, visible external damage to the elements can suggest the direction of troubleshooting and localization of the defect even before the start of the necessary measurements at the control points of the nodes of electronic circuits. Electrolytic capacitors of filters with a swollen casing, as well as ring cracks formed in the soldered leads of heating elements, or a layer of coal on burnt resistors sometimes tell the repairman the causes of the malfunction and possible consequences.
If the EADP-70AF power supply module malfunctions, the external manifestations may be different, for example, the TOSHIBA 20VL66R does not turn on at all and there is no indication of the indicator lights on the front panel. With the same symptoms, the stabilizer (converter) of the power supply to the control processor may be faulty. Diagnostics and repair of the common power supply should always begin with a check of the mains fuse and the condition of the electrolytic capacitors of the secondary rectifier filters. Defective and swollen capacitors should be replaced with new ones. If the fuse breaks, it is advisable to check for a breakdown, first of all, all the power semiconductor elements of the converter and the diode bridge of the rectifier network, as well as the large electrolytic capacitor of the filter of the rectifier network.
It should be borne in mind that in the practice of repair it is extremely rare that key transistors in switching power supplies (SMPS) fail for no reason that should be sought by checking other components, for example, a breakdown of the key can provoke faulty elements of the damper circuits, or dried electrolytic capacitors or dangling primary resistors BP circuits involved in the stabilization process. In this case, all semiconductor elements of the strapping of the PWM controller chip are subject to verification, which it is desirable to verify by replacement.
Sometimes the TOSHIBA 20VL66R TV does not have an image, but there is sound, or the image appears and immediately disappears. In this case, there is a high probability of a malfunction of the A201SN02 v.5 panel backlight LEDs converter, or a break in the LED circuit is possible. In such cases, first of all, it is necessary to verify the serviceability of all the electrolytic capacitors of the filter by supplying the LED driver itself, including in the power supply unit (power supply unit).
In most cases of lack of backlight, it becomes necessary to disassemble the panel in order to check the LEDs, connectors, loops and all contact connections. If one or several LEDs does not work in one line, therefore, they are broken and should be replaced.
It is impossible to check the LED line for breaks without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally, a current source.
When trying to repair the motherboard, you should first check the serviceability of linear stabilizers or power converters of microcircuits and, if necessary, update the software (software).
Attention to the owners! Attempts to self-repair the TOSHIBA 20VL66R TV are not recommended by the manufacturer and can lead to serious negative consequences!
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> Toshiba 20VL66C, 20VL66T, 20VL66H, 20VL66M, 20VL66R, 20VL66E, 20VL66A, 20VL65R, 20DL76
Service Manual 54 pages 2006 on model 20VL66R, 20VL65R, 20DL76
The appearance of MainBoard 4H.00501 is shown in the figure below:
4H.00501
The appearance of the power supply
Main features of the TOSHIBA 20VL66R device:
Installed matrix (LED panel) A201SN02 V.5.
The LED driver EADP-70AF is used to power the backlight LEDs.
The formation of the necessary supply voltages for all nodes of the TOSHIBA 20VL66R TV is carried out by the EADP-70AF power module, or its analogs.
MainBoard - the main board (motherboard) is a 4H.00501 module using CPU chips: PW106B-10L; AD9381, MSP3410 and others.
The ENG39A11GF tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: A201SN02 V5
Type: a-Si TFT-LCD, Panel
Diagonal size: 20.1 inch
Resolution: 800x600, SVGA
Display Mode: TN, Normally White, Transmissive
Active Area: 408x306 mm
Surface: Antiglare
Brightness: 450 cd / m²
Contrast Ratio: 700: 1
Display Colors: 16.2M (6-bit + FRC), CIE1931 72%
Response Time: 11/5 (Tr / Td)
Frequency: 60Hz
Lamp Type: 6 pcs CCFL Without Driver
Signal Interface: TTL (1 ch, 8-bit), 50 pins
Voltage: 5.0V
TOSHIBA 20VL66R LCD TV with A201SN02 LCD, 20 "diagonal size, 4: 3 format. The brightness of the screen is 450 cd / m² with CCFL (EEFL) fluorescent lamps. The ratio of maximum brightness to minimum (contrast) is 600: 1. The input high-frequency or video signal can be processed in analogue systems PAL, SECAM, NTSC. Graphic processing and digital signal generation takes place in the standards 480i, 480p, 576i, 576p, 720p, 1080i.
The power of the sound system 4 W (2x2 W) provide two speakers. The audio processing system NICAM STEREO is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV x2, audio x3, S-Video, component, VGA. 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.
The power consumed by the TV in the operating mode from the network is 50 watts.
Overall dimensions: with stand 474x465x236 mm, without stand 474x431x82 mm.
TV mass: with stand: 8.4 kg, without stand: 7.5 kg.
Attention! The A201SN02 V.5 panel of the TOSHIBA 20VL66R 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!