The last article I mentioned above Elko breakdown under load. In this article I am going through the high voltage resin coated ceramic disc capacitor speak. In computer monitor, it is often used on the screen voltage (G2) line at the crt board. If it fails, it can become irregular, or occasionally scanning light and dark and sometimes not displayed.
Adjusting the flyback transformer screen control will not solve this problem. You can isolate the problem, as if, ifthey lead by a defective fly back or G2 line at crt board. The wire from the G2 circuit and measure the voltage screen with a digital multimeter, it should remove a constant voltage (will not) vary. If the voltage is not stable suspect the fly back. If it is ok then trace the screen voltage circuit. Normally this route is composed exclusively of resistors and capacitors. Sometimes a defective CRT connector could be causing this kind of problem also!
Many times a tech can not solve this intermittent or noDisplay is a problem because their capacity and digital ohmmeter measured ok on the capacitors. The capacitors on the screen voltage line are usually rated by 102,103 and 472 1KV to 2KV. Causing a 'missed' in checking this capacitors, the technician can not solve the problem, if he directly replace the condenser. An intermittent capacitor can pull the screen, causing power problems in the presentation.
As mentioned earlier, an ohmmeter with 12V output and a digital capacity with 3vOutput are not in a position to closely monitor the capacitor, if the assessments of 1-2 kilovolt!
If you have the analog insulation tester or meter, the panel will show a short circuit when certain voltage in the high-voltage capacitor should be checked pump. The tension that you can choose depends on the brand or model that you buy. Some have the range of 50V to 1000V, and some have the range of 100V to 500V. It is optional whether you should have one. If you then it would be an additionalAdvantage for you. The other option you have is to replace direct the suspected capacitor. In my country you can get a new one in less than US150.00 or you may have a used unit on eBay.
As for me, you can equip the small blue resin coated ceramic disc capacitor, that have the capacitor code of 104 50v, in addition to the use of digital capacitance meter to check the value, I also use an analog meter 10kohm at times the output of 12V to set check this type of capacitor. Many times it iswill reveal the bad intermittent capacitor. You will be shocked to see the capacity meter checked ok but show a reading short-circuited when Analog Multimeter.
On the market there are certain brand of analog multimeter that the spectrum of 100kohm. When you open the lid, you can not see the 9V battery in it, what you see just the 2 pieces 1.5 V battery. This type of counter may not accurately reflect the short in the capacitor, since the output is only 3V!
Forthose who are involved in repairing monitor, you will agree with me that checking the flyback internal capacitance many times the correct value 2.7nf capacitance to digital meters, but when you turn on your monitor, you become a "tick-tick hear ' clay from the Inlet. This is because the capacitor is broken, if it is under load. If you did not do anything with the flyback, gradually the internal capacitance are short and you need to renovate the reverse.
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