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Repair of theTOSHIBA 20JL7R TV 

Technical description and composition of the TV TOSHIBA 20JL7R, the type of panel and modules used. The composition of the modules.

Model: 20JL7R
Panel: T201VN01 V1
LED driver (backlight): DAC-19B023 23078216
PWM LED driver: OZ960SN
MOSFET LED driver: AO4606
Power Supply (PSU): TAA-Y59 19v / 4.2a
PWM Power: 7501 (8), L6561D (PFC)
MOSFET Power: 11N65C3
MainBoard: PD1803 / PD1860
IC MainBoard: MN101E02HXX, GM2221, 24LC16
Tuner: EC981W1

Specifications 20JL7R

General recommendations for the repair of TV LCD LED

TOSHIBA 20JL7R, like other TVs, it is advisable to start to repair with a careful examination of external and internal elements and modules. Sometimes, by visible changes in the components of the device, it is possible to draw some conclusions and decide on the direction of further troubleshooting even before the start of the necessary measurements. Elements with visible damage, for example, capacitors swollen after boiling the electrolyte, charred resistors in certain nodes of the circuit, as well as ring cracks in soldering will help the master to guess the causes and possible consequences of the malfunction that occurred.
In cases when the TOSHIBA 20JL7R TV does not turn on, does not respond to the remote control and buttons, does not light or blink, there are no indicators on the front panel and there are no sounds and no signs of performance when you turn on - most likely the TAA-Y59 19v power module is faulty 4.2a or there is no processor power on the motherboard (typical defect of some TOSHIBA TVs). First of all, it is necessary to replace the swollen capacitors of the filters of the rectifiers, if they exist. If the mains fuse is interrupted in the power supply unit, in most cases the breakdown of the power switch (s) 11N65C3 is detected, which can be integrated with the PWM controller, or a separate field-effect transistor can be used. You should also check the diodes of the rectifier bridge and the electrolytic capacitor of the power supply rectifier filter.
The Mos-Fet keys used in switching power supplies (SMPS) rarely fail without reasons that need to be sought by checking other circuit elements. Often, breakdown is caused by faults in electrolytic capacitors or semiconductor elements in the primary circuit, or a break in the resistors in the stabilization circuits. The PWM controller 7501 (8) L6561D (8) chip can also be the cause of the breakdown of the power switch of the converter.
In cases when the TOSHIBA 20JL7R TV has lost the image, but there is sound and all other functions are working, there is a possibility of a malfunctioning LED driver (converter for powering the LED backlight panel 23301618). When you turn on the TV, the image may briefly appear and disappear immediately. It is necessary to take into account that the LEDs themselves also fail with such manifestations. 
In most cases, the lack of illumination arises the need to disassemble the panel in order to test the LEDs, connectors, cables and all contact connections. If one or several LEDs do not work in the same line, therefore, they are pierced and should be replaced.
A break in the lines of LEDs connected in series to detect using a multimeter or a tester is impossible without disassembling the panel. To open all the transitions, you need a few tens of volts, and it is best to use a current source for such purposes.

Remember! Attempts to self-repair users of the TOSHIBA 20JL7R TV without appropriate qualifications and the necessary experience can lead to serious negative consequences!

Download: Scheme and service manual :

Advanced by PSU

The power supply module TAA-Y59 is made using a power factor correction (PFC - Power Factor Correction) scheme in order to eliminate multiple AC harmonics introduced by the device into the power grid. The PFC node is a step-up converter based on the L6561D shim controllerwhich evenly within the period of 50 Hz distributes the high-frequency pulses of the charging current of the electrolytic capacitor of the rectifier filter of the mains voltage. The current of its charge in this case will already be determined not by its reactance (usually 10-30 ohms for the mains frequency), but by the converter elements. 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 sinusoidal input voltage. The health of the PFC node is indicated by the presence of overvoltage (about + 380V) in the operating mode on the capacitor of the line filter.
The main features of the device TOSHIBA 20JL7R:
Installed matrix (LED-panel) T201VN01 V1. 
The LED driver DAC-19B023 is used to power the backlight LEDs. It is controlled by the OZ960SN PWM controller. Keys of type AO4606 are used as power elements of the LED driver. 
The formation of the necessary supply voltages for all nodes of the TOSHIBA 20JL7R TV is performed by the power supply module TAA-Y59, or its analogues using chips 7501 (8), L6561D (PFC) and power switches of the type 11N65C3. 
MainBoard - the main board (motherboard) is a PD1803 module, using chips MN101E02HXX, GM2221, 24LC16 and others. 
The EC981W1 tuner provides television reception and tuning to channels.


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