Saturday 14 March 2020

REPAIR / SERVICING TV SHARP LC-26AD5RU-BK

Technical description and composition of the TV SHARP LC-26AD5RU-BK, type of panel and applicable modules. The composition of the modules.
SHARP
Model: LC-26AD5RU-BK
Panel: LK255T3LZ5AZ
T-CON: CPWBX3333TPBF TW10794V-0
Inverter (backlight): RDENC2267TPZC IM38 27CA 6714111
PWM Inverter: BD9777 (20)
MOSFET Inverter: TPC8110 (8) RSS085 (8)
Power Supply (PSU): CEF273A MP2A5060
PWM Power: MIP2F4 (Standby), MP2A5060
MainBoard: CMF111B // NP-140TL
IC MainBoard: VCT6973G-B3-000, SIL9025CTU, TDA9832T
Control: IR: CEF275A
Technical Specifications LC-26AD5E
SHARP LC-26AD5RU-BK
General recommendations for repairing TV LCD
It is advisable to start any repair and diagnostics of the SHARP LC-26AD5RU-BK TV with a careful external examination of internal and external elements, including case parts, a display, buttons and cables. Any external damage can sometimes prompt the repairman to take further steps to determine the malfunction of the TV and localize the defect. Carbonized paint on the upper layer of resistors, electrolytic capacitors of rectifier filters swollen after boiling, cracked soldering at the terminals of heating elements or transformers can often suggest the cause of the defect and possible consequences.
Faults in the CEF273A (6) MP2A5060 power module can be expressed in different ways, for example, the SHARP LC-26AD5RU-BK does not turn on at all and the control lights on its front panel do not light up and do not blink, and there are no signs of operability. In this case, the diagnosis and repair of the common power supply should always be started by checking the mains fuse. When it breaks, it is advisable to check for a breakdown, first of all, all power semiconductor elements of the converter and the rectifier diode bridge of the network, as well as the large electrolytic filter capacitor of the network rectifier and the key transistor.
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 MIP2F4 PWM controller chip itself may be faulty (8). It is also necessary to check all the semiconductor elements of the stabilization circuit in the primary and secondary circuits.
Diagnostics of power modules with a Power Factor Corrector (CMC) is somewhat more complicated and requires a more detailed approach.
If the SHARP LC-26AD5RU-BK TV does not have an image, but there is sound, the malfunction should be sought in the power converter of the backlight (inverter). It is also necessary to check the serviceability of the electrolytic capacitors of the filter of the secondary rectifiers of the PSU (power supply) for an overstated ESR.
Often, attempts to repair an inverter RDENC2267TPZC IM38 27CA are complicated by the fact that the diagnosis of a malfunction is complicated by the operation of its protection, which is designed to turn off the inverter in emergency conditions - when the lamps are depressurized, breaks or short circuits in high-voltage connections and other emergency situations. Lock protection to localize the defect is popular among repairmen.
In such cases, special care should be taken during diagnostics, and after completion of all repair work, it is necessary to restore the circuit and the inverter protection for further safe operation of the TV.
In cases of attempts to repair the motherboard NP-140TL, it is necessary to check the operability of the power stabilizers of the microcircuits and, if possible, update the software (software).
Owners and users of the SHARP LC-26AD5RU-BK TV must remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!

Service manual / schematic diagram ------------>    Sharp LC-26AD5E-BK
 Service Manual with Schematic Diagram 90 pages 2007  model LC-26AD5E-BK

 The appearance of the MainBoard CMF111B is shown in the figure below:
CMF111B
CMF111B can be used in TVs:
SHARP LC-26AD5RU-BK (Panel LK255T3LZ5AZ), SHARP LC-32AD5RU-BK (Panel LK315T3LZ5CZ LK315T3LZ93), TOSHIBA 32W300P 32W300Ps (Panel LC320W01 (SL)(22) ).
The appearance of the power supply
Main features of the SHARP LC-26AD5RU-BK device:
Installed matrix (LCD panel) LK255T3LZ5AZ.
The matrix control uses the Timing Controller (T-CON) CPWBX3333TPBF.
The RDENC2267TPZC inverter is used to power the backlight, controlled by the BD9777 PWM controller (20). As power elements of the inverter, keys of the type TPC8110 (8) RSS085 (8) are used.
The necessary supply voltages for all nodes of the SHARP LC-26AD5RU-BK TV are generated by the CEF273A power module or its analogs using MIP2F4 (Standby), MP2A5060 microcircuits.
MainBoard - the main board (motherboard) is a CMF111B module, using VCT6973G-B3-000, SIL9025CTU, TDA9832T and others.