Dell LCD monitor E151FPb came to the complaint can not but consider carefully the LCD screen could see a very slight (Blur) white flashes on the screen and the LED Supply is not illuminated. Removing the front was a bit easy compared to other models. As usual whenever the motherboard and the power of the card has been grounds, I would look for any bulging capacitors dark, a loose connector and advice, etc. However, this monitor seems perfectly correct. The following step was to separate the power or the inverter board with the main board. Power was applied to the power card and I could hear Â'chip good sweet corn cake. When measuring the line of 12 volts with a digital multimeter, the reading was approximately 7 to 8 volts, which was very unusual. In fact, this is good news for us, because we know what the next step that we must do.
Now we can use a 12 volt bulb automotive brake to test in that section which raises the output low voltage problem. If the LCD monitor designed to operate in 18 or 24 volts, then you can use a bulb in the semi-trailer. A faulty component in primary or secondary, can cause low blood flow. By removing the fuses, as shown in the photo and contact between the bulb line supply and the cold could say that the section is crashing. You could use this method, but first must confirm that the secondary projection condensers, TL431 adjustable shunt Precision regulator IC, OPTOISOLATOR and surrounding components OPTOISOLATOR work before continuing with the use of light bulb.
When the device is switched the bulb are not yet lit, and noise could still be heard. This indicates that the primary side is having problems and we can get out of the frequency of Unit / high voltage area and concentrate fully to locate defects in the primary section.
It is time to really test their basic skills electronics, because they now know what area of the fault and should only use their skills to find the exact bad component. There were many components to the primary side, and can easily check all in 20 minutes. After checking all the components I was surprised that all tested well. Transformer primary winding change of power rings 8 bars indicating good and even power PWM IC uc3842b wonÂ't replaced power still works! It was a real challenge to resolve such of problem where you can be one hundred percent sure that the main problem continues it could not find the culprit.
As I tested all the components and could not find the fault, the only way you could do is replace lead semiconductor devices such as diodes, SCR, FET, and transistors. From experience, I met breakdown of semiconductor components, when under operating voltage. One by one the semiconductor components, replacing and growing food had changed to see if the bulb or not. You know what, you would not believe what I just found a 2N7000 FET defective! The moments which replaced the power FET and bulb lights immediately. I could not believe that it was defective fet all the stresses that cause output to drop! I was so happy that finally solved the problem and Who knows what could be a defect common to all LCD Monitor Dell E151FPb-please take note to all LCD repair.
I started to verify the new FET 2N7000 wrong with my meter and analyzer analog electronics advanced components of Atlas and the result is always the same taste good! As a flyback, the best test equipment to test FET and other components is actually the material itself, as it runs at full operating voltage, signal frequency, etc. What you just learn from here is that if all the suspects tested good, the only way to reveal the truth is that direct substitution. We hope you enjoy this article and more good items every day! We wish him well and happy to repair!
Jestine Yong is a electronic repairer and a writer, for more lcd monitor repair tips and secrets, please visit his website at http://www.electronicrepairguide.com/lcd-monitor-repair.html
