Saturday 7 March 2020

REPAIR / SERVICING TV SONY KDL-40U4000

Technical description and composition of the SONY KDL-40U4000 TV, panel type and applicable modules. The composition of the modules.
SONY
Model: KDL-40U4000
Chassis / Version: EG1L-L
Panel: LTY400HA11
T-CON: 400HAC2LV3.0
Inverter (backlight): SSB400W16S01
PWM Inverter: LX1692BIDW, LM339DT
MOSFET Inverter: 2SK3569
Power Supply (PSU): IP5 1-876-467-21 - M1556720A - A1556720A
PWM Power: R2A0112 (PFC), CXD9841P, MIP2H2 (Standby)
MainBoard: 1-877-114-12
IC MainBoard: UPD61123F1, HYB25DC256160CE, TPA3100, M24C32
Tuner: BTD-HF411T
Control: IR: 1-877-115-11 172988011
Technical Specifications KDL-40U4000
SONY KDL-40U4000
General recommendations for repairing TV LCD
Possible manifestations of defects
- SONY KDL-40U4000 does not turn on and does not show any signs of operability. Does not blink indicators and does not respond to control buttons.
Failure in such cases should be sought in the IP5 power supply circuits. It is necessary to measure the output voltages in its secondary rectifiers, and in case of their absence, check the serviceability of the power switches of the converters and rectifier diodes for possible breakdown (short circuit).
First of all, you should check the standby power converter on the MIP2H2 PWM controller.
It must be remembered that in the event of breakdowns in the secondary circuits, the converters can fail in short circuit mode, and during a short circuit in the power elements of the primary circuit, the mains fuse 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 the excess of maximum current or voltage values. These can be circuits supplying PWM, damping and frequency-setting circuits, or elements of OOS (negative feedback) stabilization.
 PWM controllers (PWM) R2A0112 (PFC), CXD9841P, MIP2H2 (Standby) are checked by replacing with obviously good ones.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
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 inverter. If all the electrolytic capacitors of the filter according to the power supply of the inverter are working, make sure that the lamps are working, then you need to check the converter keys and the secondary windings of the transformers.
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, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the motherboard 1-877-114-12 should begin by checking the stabilizers and power converters needed to power the microcircuit and matrix. If necessary, update or replace the software (software).
Before changing the Tuner tuner, if there is no possibility of tuning to television channels, you should make sure that there are supply voltages, which must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Once again, remind users! Attempts to self-repair a SONY KDL-40U4000 TV without the appropriate qualifications and necessary experience can lead to its complete non-repairability!


Service manual / schematic diagram --------------->   SONY KDL-40U4000 Chassis EG1L-L

Service manual / schematic diagram --------------->   Sony 1-876-467-11, 1-876-467-21 IP5 Power supply



 The appearance of MainBoard 1-877-114-12 is shown in the figure below:
1-877-114-12
1-877-114-12 can be used on TVs:
SONY KDL-40L4000 K (Panel LTZ400HA07 A03), SONY KDL-40V4210 (Panel LTZ400HA07), SONY KDL-46V4000 (Panel LTY460HB08 002), SONY KDL-40U4000 (Panel LTY400HA11).
The appearance of the power supply
Main features of the device SONY KDL-40U4000:
Installed matrix (LCD panel) LTY400HA11.
The matrix control uses the Timing Controller (T-CON) 400HAC2LV3.0.
To power the backlight, an inverter SSB400W16S01 is used, it is controlled by the PWM controller LX1692BIDW, LM339DT. As power elements of the inverter, keys of the 2SK3569 type are used.
The necessary supply voltages for all nodes of the SONY KDL-40U4000 TV are generated by the IP5 power supply module, or its analogs using the R2A0112 (PFC), CXD9841P, MIP2H2 (Standby) microcircuits.
MainBoard - the main board (motherboard) is a module 1-877-114-12, using microchips UPD61123F1, HYB25DC256160CE, TPA3100, M24C32 and others.
The BTD-HF411T tuner provides TV reception and channel tuning.