Monday 9 March 2020

REPAIR / SERVICING TV SONY KDL-40WE663

Technical description and composition of the SONY KDL-40WE663 TV, panel type and applicable modules. The composition of the modules.
SONY
Model: KDL-40WE663
Panel: NS7S400HND01 (4-687-935-22)
Inverter (backlight): A2194442A
Power Supply (PSU): Adapter 19.5V
MainBoard: 1-981-541-21 (A21944442A)
IC MainBoard: MT5581SSEJ, 25Q16, D4758GG
Tuner: CE251ZP
Technical Specifications KDL-40WE663
SONY KDL-40WE663
General recommendations for repairing TV LCD
Possible manifestations of defects
- The SONY KDL-40WE663 TV does not turn on. There are no signs of operability. The indicators on the front panel do not light up and do not blink, the TV does not respond to the control buttons.
In some of these cases, a malfunction is detected in the adapter power module.
The owner of the TV can purchase an external power adapter adapter 19.5V type independently and its repair is not always advisable. In any case, the simplest typical defects characteristic of most IIP schemes can be easily detected and eliminated after opening. It is then necessary to measure its output voltages and, if they are absent, it is necessary to check the power switches and rectifier diodes of the converters for a short-circuit probability.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in emergency short-circuit mode without output voltages, and during short circuit in the elements of the primary circuit, the main fuse and, less often, the current sensor at the source of the key are most often cut off.
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), in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, but there is sound and all other functions work. Sometimes when you turn on the image for a second appears and disappears.
These manifestations can be triggered by a power module, or by defects in the inverter, as well as a distortion of the currents in the lamps due to their uneven wear. If all the electrolytic capacitors of the filter according to the inverter power supply are serviceable, you should make sure that the lamps are working, then you need to check the converter keys and the secondary windings of the transformers.
If in diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during work, and after they are finished, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- The indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the motherboard 1-981-541-21 should begin by checking the stabilizers and power converters needed to power the microcircuit and matrix. If necessary, update or replace the software (software).
TV users and owners need to remember that attempts to self-repair a SONY KDL-40WE663 TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!




The appearance of MainBoard 1-981-541-21 is shown in the figure below:
1-981-541-21
Main features of the device SONY KDL-40WE663:
Installed matrix (LCD panel) NS7S400HND01 (4-687-935-22).
The inverter A2194442A is used to power the backlight.
To power all the internal components of the SONY KDL-40WE663 TV, an external adapter 19.5V type source is used.
MainBoard - the main board (motherboard) is a module 1-981-541-21, using microchips MT5581SSEJ, 25Q16, D4758GG and others.
The CE251ZP tuner provides TV reception and channel tuning.