Technical description and composition of the TV SHARP LC-37XD1E, type of panel and applicable modules. The composition of the modules.SHARP
Model: LC-37XD1E
Chassis / Version: KD915WE07
Panel: 37 inch
T-CON: CPWBX3348TPZS
Inverter (backlight): RUNTKA 244WJZZ-245WJZZ
Power Supply (PSU): DUNTKD787WE (DUNTKD787WE02)
PWM Power: MR4040, FA5501A (PFC)
MainBoard: KD915 KD915WE07
IC MainBoard: FRC9429A B2, MSP4410K D6, TDA8931T
Tuner: KD833
Control: GA538WJSA
Technical Specifications LC-37XD1RU
SHARP LC-37XD1E
General recommendations for repairing TV LCD
It is advisable to start repairing the SHARP LC-37XD1E TV with an external examination of all its constituent elements, both internal electronic components and external. Inspection is also subject to body elements, control buttons, screen, connectors and cords. Often, for certain external signs, the repairman can draw some conclusions about the reasons for the failure of certain elements of the circuit even before the necessary measurements are made, which will determine the further algorithm for troubleshooting and localizing the defect. 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.
In cases where the SHARP LC-37XD1E TV does not turn on, does not respond to the remote control and buttons, no indicators on the front panel light up or blink, and there are no sounds and no signs of operability when turning on, the DUNTKD787WE02 power supply module is most likely faulty or, which is much less common - there is no processor power on the motherboard. The diagnostics of the power supply should always be started by checking the fuse and, if it is broken, it is first necessary to check the rectifier bridge diodes and the power switch for the possibility of an avalanche or thermal breakdown.
It should be remembered that in the practice of repair, usually the power keys of N-Fet converters do not fail due to their poor quality and, in such cases, it is necessary to look for the cause that led to a malfunction and provoked a breakdown of the key. Most often, the culprits of the accident are dried electrolytic capacitors or dangling resistors in the primary circuit, or the MR4040, MR4040, FA5501A, YG972S6 PWM chip itself may be faulty. It is also necessary to check all the semiconductor elements of the stabilization circuit in the primary and secondary circuits.
If the power module uses an active KKM circuit (power factor control), troubleshooting is somewhat more complicated.
If, when you turn on the TV, the image appears and immediately disappears, or is initially absent when you turn on, but there is sound and other functions work, there is a high probability of a malfunction of the inverter (power converter for the backlight). In such cases, the lamps, the inverter and the common power module are subject to verification, in which the electrolytic capacitors of the rectifier filter feeding the inverter should be checked.
Repair of the RUNTKA 244WJZZ-245WJZZ inverter is complicated by the fact that in case of any malfunction or emergency, even if the lamps are unevenly worn, protection is triggered, which turns it off for fire safety. Diagnostics become impossible and protection needs to be disabled.
In such cases, the risk of failure of the power elements of the inverter is most likely, and special care is required during work, and after their completion, it is necessary to restore the protection circuit for further safe operation of the TV by the owner in normal mode.
In cases of attempting to repair the KD915WE07 motherboard, it is necessary to check the operability of the power supply stabilizers for the microcircuits and, if possible, update the software (software). In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its chips FRC9429A B2, MSP4410K D6, TDA8931T and other possible faulty components.
Before replacing the KD833 tuner, if there is no tuning to the channels, you must first check the supply voltage at its terminals, including the varicap supply (30-33V).
It should be remembered! Attempts to repair the SHARP LC-37XD1E TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!
Service Manual with Schematic Diagram 98 pages 2006 model LC-37XD1E, LC-37XD1RU, LC-42XD1E, LC-42XD1RU.
The appearance of the MainBoard KD915 is shown in the figure below:KD915
PSU Advanced
The DUNTKD787WE02 power module is installed in the LC-37XD1E TV using the PFC (Power Factor Correction) scheme acting as an active filter to eliminate the higher harmonic components of the current consumption. The step-up converter based on the FA5501A PWM controller does not allow the input rectifier filter's electrolytic capacitor to be connected to the network directly through open diodes, when the value of the charge current determines its reactance (about 15-30 ohms at a frequency of 50 Hz). As a result of the conversion, the charging current of the capacitor will be determined in such a way that the envelope of the high-frequency pulses of the input current will repeat the phase and shape of the sine wave of the input voltage. The health check of the PFC unit is carried out by measuring the DC voltage on the capacitor of the rectifier network. In operating mode, it should be around 380V, in standby approximately 300V.
The appearance of the power supply
Main features of the SHARP LC-37XD1E device:
Installed matrix (LCD-panel) 37 inches.
The matrix control uses the Timing Controller (T-CON) CPWBX3348TPZS.
To power the backlight used inverter RUNTKA.
The necessary supply voltages for all nodes of the SHARP LC-37XD1E TV are generated by the DUNTKD787WE power module or its analogs using MR4040, FA5501A (PFC) microcircuits.
MainBoard - the main board (motherboard) is a KD915 module, using the FRC9429A B2, MSP4410K D6, TDA8931T chips and others.
The KD833 tuner provides TV reception and channel tuning.
