Today's article deals with the repair of the CMV 19 "LCD Monitor problems model CM-922D. The Board has no power as what the customer needs to see me. This power supply was not built into the circuit as a external power supply is even more power. The entrance to the LCD monitor and 3.1 amp 19V from the board. Given that the complaint is electricity, we must try to see if the power supply is at fault or the LCD monitor.
The AC power is connected to the mains and Icould see the power LED that was illuminated. Check the output voltage of the supply of power, I have about 19 volts, which is good. Even if the LED is lit, and the output voltage correct, this does not mean that the power supply to maintain, if (a load of the LCD), can be connected. Once entered into a Compaq 17 "LCD monitor that displays a precise output voltage from the power supply, but if the monitor is connected, the display for a split second before turning off.A rule in this case, your experience, when you say that could be the inverter circuit are faulty or the problem of the lamp. You would be surprised that the real reason for the closure is due to the mains. You can not sustain the output voltage when a load on them.
This type of error has generally been removed due to a faulty capacitor filter output of the secondary circuit. If you have ESR meters, you can actually locate the defective electrolytic capacitors quickly. If younot have the counter, just replace the caps directly. As noted in my previous repair to confirm if the power really works or not, must act as a cargo lamp. Make sure that the power LED is not flashing when the bulb is connected. Although flashes once, this shows that the system is good, and examined in depth. Made in China, above the LCD monitor, the adapter work fine!
As I have already confirmed that thePSU is good, my focus is now on LCD panels. Remove this cover was very easy and can be easily accessed from the board, when the metal was housing. The first thing I checked was the fuse in the main board SMD. If the fuse opens then there would be the transfer of ADC / Scalar and IC CPU then the power LED does not light! If you use this SMD fuse was rather simple as the method of control is the same as a normal backup. Use an analog or digitalMeter set to check the continuity of supply and ohms. You can verify the backup while still in the circuit. Yes, it is determined to ensure that the cargo.
Now there's an issue that must be resolved by us. What does the idle go up? Well, what we have experienced electronic repair, there are three possibilities, how, why you open a fuse circuit. First, the backup will be inactive because of its duration. Some fuses can for many years, while others only two years. OtherWords depends on the life of a backup on the properties of materials used. Secondly, external factors, like a wave caused the fuse to the circuit to protect the mother to open. Thirdly, the main board itself the problem (eg a short circuit IC) 'if other electronic components, causing the fuse to open circuit.
When the LCD Monitor problems falls to the first and second category, then the fuse will definitely solve the problem. But for this LCDMonitor, replacing only the fuse at all, and again up the workload. They have only two ways to solve this problem. First, it could use an external power supply regulated, like me) in my previous repair articles and connect the negative output power ground and the positive impact on the backup (the one that leads to different circuits to detect the short circuit . Slowly, the output voltage and monitoring the current consumption of soft. Once the current draw onan amplifier or two, then place the finger on other electronic components on the motherboard. If you find all the components that are very hot, then that is the cause of the short circuit.
In this article, I will do differently to detect the short circuit. Are you ready? Now exists to replace the fuse with the accurate assessment of 3 amperes, I replaced it with a 5 amp fuse. The goal for me, the 5-amp fuse instead of the 3-A fuse was because "if the fuse is not the blowComponent that goes beyond short-circuit have. "Do you get the idea?" Three things can happen when you use this way to force out the culprit. First to break the power supply may shut down due to heavy current draw from the motherboard. Secondly, the short-circuit electronic components (or IC, diodes, capacitors, transistor and etc) is hot and you can find them quickly by lightly touching them. Remember not to be too long if the components of the circuit is too hot, will be openCircuit and now have a difficult time looking for the error. Thirdly, you may hear a pop sound and spark from the shorted component. Track of where the spark came from and you can easily identify the location and, sometimes, the actual component that generate the spark.
For the above LCD Monitor, I actually saw a little spark at the top of the main board once the power input jack is connected. It brought me to the exact location, and if the SMD ceramic capacitor (iegenerates a spark under him) with analog meter set to X 10 K ohm range, has actually developed a slight short circuit. Replace the fuse and the SMD ceramic capacitor has not solved the problem of power in this 19 "monitor LCD. The monitor uses the inverter IC (OZ960G) A1084-25 centimeters (2.5 volts voltage regulator), AMC1117 - 3, 3 (3.3 volts voltage regulator), IC (ADC MST8136B) and CPU IC (MYSON MTV312MV64).
Conclusion There are always options available, the methods that you want to useDetection of short circuit. If you prefer the latter, then I suggest you take some shots of photos before something really indescribable gutted. With photos, at least that will give you some clues about what components to be or even part numbers. Well, there's always an interesting way to solve the problems of electronics and this is one reason why I repair electronic equipment, as much because there is always acting as a detective for the author-a real satisfaction! Oh Ofway, you can use the above method to other electronic devices, and is not just limited to the repair problems. They have a great game my friend!
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