The Right Way To Discharge Capacitor In Switch Mode Power Supplies by Jestine Yong
Switch mode power supply contain some large filter capacitors that can hold dangerous charges even if the unit has not been used for several days. Typical values of this type of filter capacitor are 220uf 250volt and 330uf 400volt! If you are going to work on the power supply circuits, it's a... There are three ways to discharge the big filter capacitor in a power supply. ... The reason for not using the screw driver to discharge a capacitor is because -the printed circuit board or circuitry can be damage due to the spark generated while discharging the high voltage capacitor.

Testing Capacitor-How To Test A Capacitor When Breakdown Under Load by Jestine Yong
Have you ever come across power problem where once you switch on the power supply and the fuse blow? You have checked all the components in the power (primary) and secondary section and all the components seems to be ok! Where is the fault? A fuse blown are usually caused by a shorted bridge... If you have the SENCORE TEST EQUIPMENT such as the sencore lc meter LC102 OR LC103, these meters have the capabilities of checking any type of capacitors with four tests: -testing for capacitor values -checking for leakage -equivalent series resistance (ESR) and -Dielectric absorption It can...

How To Repair Dell E153Fpc LCD Monitor With Shutdown Problem by Jestine Yong
Repairing the DELL E153Fpc LCD Monitor with the complaint of display shutdown after few seconds (power LED still on) was not difficult. Normally when this type of problem happens, we would first suspect the inverter board, then the filter capacitors and lastly the main board. ... By the way, the voltage at the bad filter capacitor line is 12 volt. ... Upon scanning for any bad components before starting the voltage test, I found a filter capacitor that had turned into darker color. ... This filter capacitor located at C922 with the value of 1000 micro farad 16 volt.

JVC VCR Problems In Model HR-J321EM-No Power by Jestine Yong
A customer sent me a JVC HR-J312EM model VCR for repair. The complaint was no power. I personally don’t repair VCR because I’m more on computer monitor repair. Because of he is a friend of mine; I told him that I’m willing to take the challenge to repair it. ... Come back to the VCR player, after opened up the casing and placed my probe on the two pins of the main filter capacitor, I could see the capacitor still holding the charge. ... There must be a reason as to why the main filter capacitor still holding the charge.

Understanding TOP223P And PQ05RD11 IC In Thompson DVD Power Supply by Jestine Yong
The TOP223P pulse width modulation ic is designed to work in switch mode power supply (smps). It is mainly used in the audio/video electronic equipment. Computer monitor rarely use this type of ic. In this article, I would like to share with you that not all switch mode power transformer must... If the output voltage has only 2-3 volts then suspect a low dc input voltage problem, a faulty voltage regulator, a high esr ohm in filter capacitor or even bad components somewhere further down the line.

Samsung 153V LCD Monitor Power Supply Repair Tips by Jestine Yong
Troubleshooting Samsung 153V LCD power supply is just like troubleshooting those crt type. This monitor came in with no power symptom. If you are first time repairing this type of power supply, I recommend you to first remove the switch mode power transformer. ... By the way the filter capacitor is rated at 105 Celsius and you cannot replace it with the 85 Celsius type otherwise it may open up again after using for couple of weeks or months. ... If there are DC voltages present at the output, you can switch off the power, discharge the filter capacitor (for safety purposes), remove the...

ATX Power Supply Repair And Troubleshooting by Jestine Yong
Customer ATX power supply came in with the complaint of intermittent no power. When testing it with power on, I could see that the fan is not rotating. Not only that, some filter capacitors also became bulge because of the heat accumulated inside the power supply. ... Diodes run a little bit hotter in filter circuit than diodes in other circuits due to the high current present at the secondary output line. ... After the equipment work for a long time and the heat generated inside the equipment will turn the glue into conductive and sometimes would even corrode the pins of the components...

How To Repair Dell E151Fpb LCD Monitor - No Display Problem by Jestine Yong
Dell E151fpb LCD monitor came in with the complaint of no power but upon carefully look at the LCD you could see a very light (blur) white flashes across the screen and the power LED is not lit. Removing the cover was a bit easy compared to other models. ... As usual whenever the mainboard and power board were exposed, I would look for any bulged capacitor, darkened area, a loosen connector and etc. ... You could use this method but first you must confirm that the secondary filter capacitors, TL431 adjustable precision shunt regulator ic, optoisolators and components surrounding the...

How To Troubleshoot And Repair DELL E151FP LCD Monitor With No Power Problem by Jestine Yong
The DELL E151FP LCD Monitor came in with no power symptom and upon opening up the cover I saw few components that were burnt. R623 (4.7 ohm) burnt at the side and you could still recognized the resistor color code. The current sense resistor (0.68 ohm) outer layer partly had came off and... The best place to put the light bulb is the fuse holder area. ... Remove one of the fuse lead and connect the light bulb across it. ... I would first use a 100watt light bulb connected in series with the live line.

What Is An LCD TV? by Julia Hall
In an LCD TV or "transmissive" display, a light source shines through a panel of liquid crystals in order to display an image. A white diffusion panel behind the LCD redirects and scatters the light evenly to provide a more uniform image than most competing technologies. ... Another benefit of owning an LCD TV is the energy efficiency of this technology. ... This keeps image burn-in from being a problem which is good news in particular for people who might use a video gaming system or PC on their TV.