Today's "Sharp" 26-inch, the fault is the indicator light red, press the remote control or panel button indicator does not respond, initially judge the motherboard something. The internal organs of this machine are as follows:
First scan the two components on the board for drums and burnt. Hey, visually, there are no component anomalies. The next step is to measure the voltage, 12V, 5V are normal, only 1.2V is 0V. Measuring 1.2V three-terminal IC input pin is 0.7V, obviously something, normal should be 3.4V, follow this road forward check, found that there are two step-down diodes 1N4007 in series, the front of the diode is 5V, as shown
The negative electrode is 1.5V, which should be 4.2V.
OK! The bad pieces have been found. In other words, the diode negative voltage is 4.2V.
1.2V regulator IC restored to 3.4V
Repaired "Sharp"
There is also a small trick. When the push tube on the high pressure strip is broken, it can be replaced with BUZ91, K2645, 10N60, 12N10, K1117, etc.
Dedicated.
Shenzhen ChengRong Technology Co.,Ltd. , https://www.dglaptopstandsupplier.com