Today’s article talks when it comes to repairing the CMV 19″ LCD Monitor difficultnesses model CM-922D. The complain was no power as what the client told me. This power supply was not built into the circuit thence it need an external power adapter to power it up. The input to the LCD Monitor is 19V with 3.1 Amp from the adapter. Since the complain was no power, we have to test it out to check if the power adapter is at fault or the LCD Monitor.

The ac supply was plugged in to the power adapter and I could see the power LED was lighted up. Checking the output voltage of the power adapter I got in regards to 19 volts which is good. Even even though the LED has lit and rectify output voltage, this doesn’t mean that the power adapter may maintain when there is a load (the LCD Monitor) connected to it. I once came all over a Compaq 17″ LCD Monitor that have a precise output voltage from the power adapter but when connected to the Monitor, the display appeared for a fraction of a second before shutting down. Usually in this case, your experienced would tell you that it could be the inverter circuit are defective or the lamps have problem. You would be amazed that the actual cause of the shutdown was due to the power adapter. It can’t sustain the output voltage when there is a load on it.

This kind of fault was ordinarily due to a bad filter capacitors located at the output of the secondary circuit. If you have ESR meter, you may actually locate the faulty electrolytic capacitors fast. If you don’t have the meter, just direct replace the caps. As brought up in my former fix articles, to affirm if the power adapter is genuinely working or not you need a light bulb to act as a load. Make sure the power LED light doesn’t blink whenever the light bulb is connected. Even if it blinks one time, this proves that the regulation is not good and need to be check entirely. In the above china made LCD Monitor, the power adapter work perfectly fine!

Since I have already confirmed that the power adapter is good, my focus now was on the LCD boards. Removing this cover was very easy and you may effortlessly access to the board when the metal casing was removed. The original thing that I checked was the SMD fuse located in the main board. If the fuse opens then there would be no supply to the ADC/SCALAR and the CPU IC thence the power LED would not light! Checking this SMD fuse was rather simple as the method of checking it is the same like a normal fuse. Use either an analog or a digital meter set to ohms range or continuity check. You may check the fuse while it is still in circuit. Yes, the fuse was found to be open circuit.

Now there is one question that needs to be answered by us. What makes the fuse to go open circuit? Well from what we have known regarding electronic repair, there are three possiblenesses as why a fuse opens circuit. First, the fuse may become open circuit due to it is lifespan. Some fuses may last for a heap of years while numerous only couple of years. In other words, the life span of a fuse depends on the calibers of the materials used. Secondly, the external factor such as a surge causing the fuse to open circuit in order to protect the main board. Thirdly, the main board itself have problem (such as a shorted IC’s and other electronic components) that caused the fuse to open circuit.

If the LCD Monitor problems falls in the initial and the second categories then replacing only the fuse will unquestionably solve the problem. However, for this LCD Monitor, replacing only the fuse didn’t work at all and the fuse open circuit again. You have only two selections to solve this kind of problem. First you may use an external regulated power supply as explained in my former fix articles and connect the negative output of the power supply to ground and the positive to the fuse (the line that leads to other circuitry) in order to observe the short circuit. Slowly vary the output voltage and monitor the current drawn. Once the current drawn in regards to a amp or two, now place your finger to any electronic elements in the main board. If you found any constituents that get very hot then that is the cause of the short circuit.

In this article, I’m going to do it differently to observe the short circuit. Are you ready? Now rather of replacing the fuse with the precise rating which is 3 amperes, I substituted it with a 5 amperes fuse. The intention for me to put the 5 amp fuse rather of the 3 amp fuse was because “if the fuse doesn’t blow then the element that have short circuit would blow”. Do you get the idea? Three things may occur when you use this way to strength out the culprit. First the power adapter may shut down due to heavy current draw from the main board. Second, the short circuit electronic constituents (either be a IC, diode, capacitors, transistor and etc) will get hot and you may speedily locate it without apparent effort by touching them. Remember don’t on it for too long other than as supposed or expected if the shorted constituents get too hot it will go open circuit and now you will have a hard time to locate the fault. Third, you may listen a pop sound and spark from the shorted component. Trace from where the spark came from and you may without apparent effort discern the emplacement and at times to the actual element that generate the spark.

For the above LCD Monitor, I genuinely saw a little spark at the top portion of the main board once the power input jack was connected. It prompted me to the precise emplacement and when I check the SMD ceramic capacitor (that generated the spark underneath it) with analog meter set to X 10 K ohm range; it genuinely invented a slight short circuit. Replacing only the fuse and the SMD ceramic capacitor solved the no power problem in this 19″ LCD Monitor. This Monitor uses the inverter IC (OZ960G), A1084-25CM (2.5 volts voltage regulator), AMC1117-3.3 (3.3 volts voltage regulator), ADC IC (MST8136B) and CPU IC (MYSON MTV312MV64).

Conclusion-There are always choices as to which methods that you want to use to observe the short circuit. If you prefer the latter one, then I suggest you to take some photo shots basi before anything actually burnt out beyond description. With the photos, at least it will give you some hints of what the elements might be or even the share numbers. Well, there’s always an interesting way to solve electronic difficulties and this is one of the reason that I like electronic fix so much because you may always act as a detective to find out the culprit-real satisfaction! Oh! By the way, you may use the above method to any other electronic instrumentation and it is not fixed only to troubles repair. Have a great hunt my friend!

Acer Computer Repair Locations Pic

Acer Computer Repair Locations Picture

Acer Computer Repair Locations Pic

Acer Computer Repair Locations Picture

Most helpful client reviews

14 of 14 humans found the following review helpful.
Exceeds Expectations
By J. Simpkins
Before receipt of this alternate adapter for my Aspire One D250, I was expecting something a little lighter and less durable. Although the adapter is little equated to the original, it performs just as well and weighs sufficient to not be a burden or to be capable to call it a cheap paperweight. Overall, I am impressed with the product. The inclusion of a green LED on the adapter is nice. It makes finding an active power outlet on campus more quickly than digging out my netbook and plugging it in, only to find that the available outlets are dead, and then having to pack up again. It is a little bit shorter overall cable-length wise, but I only purchased this to have an adapter to carry with me and leave the firstborn at home.

I highly commend it for the price and quality.

9 of 9 humans found the following review helpful.
It works as good as the original
By Burton M. Pierce
I went to Acer and ordered this item on the 10th with expedited shipping because it was a repair part. On the 15th I called to find out that it had been placed on backorder and I “should” get it in a few days. I canceled the order and placed with Brilliant store on the 15th and got it on the 16th at almost half price.

My reccomendation is to not go to the PC mfg for constituents you may replace yourself.

I also want to thank Brilliant Store for their great service, the percentage was here before the Amazon shipping e-mail.

6 of 6 people found the following review helpful.
Works Great!
By M. Warren
This works great with my Aspire One. It is littler and the wires are shorter than OEM, but the overall construction is still good. Given that Aspire wanted $60 for a factory original replacement, I consider this to be a bargain and am glad that I purchased it.

See all 64 client reviews…