In this article I’ll talk about the high voltage resin coated aluminum electrolytic capacitors. In computer monitor, it truly is regular used within the display voltage (G2) point at the crt panel. If it fails, it may cause erratic or occasionally raster bright and dim and occasionally no screen.
Adjusting the fly-back transformer screen control isn’t going to fix this problem. It’s possible for you to separate the difficulty as whether when it cause by a flawed fly-back or G2 point at crt panel. Eliminate the G2 wire from signal and quantify the display current with a digital multi-meter – it needs to have a constant voltage (will not fluctuate). In case the voltage is not secure suspect the fly back. When it OK then outline the display voltage circuit. Frequently this signal include only resistors and capacitors. Occasionally a faulty crt plug might cause this sort of trouble additionally!
Often times a tech can’t resolve this spotty or no show issue is because their electronic capacitance and ohmmeter assessed OK to the aluminum electrolytic capacitors. The aluminum electrolytic capacitors in the screen current line are generally ranked of 102,103, and 472 1kv to 2kv. A ‘missed’ in checking this capacitors will caused the technician can’t answer the problem, unless he direct replace the capacitor. The screen voltage can be pulled down by an intermittent capacitor creating the display issue.
When you have the analog insulation tester or meter, a short circuit will be shown by the panel when particular voltage are pump into assess the high voltage capacitor. The currents which one may pick is really depends on the brand or model you buy. Some have the range of 50v to 1000v and some have the range from 100v to 500v. It really is discretionary whether you need to have one. It would surely be an additional edge for you in case you have one then. Another option you have would be to immediate replace the thought aluminum electrolytic capacitors. Inside my country, you can get a brand-new one in just less than US150.00 or you could bid a used device from e-bay.
As for me, examining the little blue resin-coated ceramic disk capacitor that possess the capacitor code of 104 50v, besides using electronic capacitance meter to check for the voltalue, in addition, I use an analogue meter set to instances 10Kohm that possess the result of 12v to test this type of capacitor. Many times it will revealed the awful sporadic aluminum electrolytic capacitors. You are going to be shocked to see the capacitance meter examined OK but show a shorted studying when test with analog multimeter.
In the marketplace there is certain manufacturer of analogue multimeter which possess the range of 100kohm. In case you open the cover, you can not understand the 9v battery in it, that which you see only the two pieces of 1.5v battery. Since the output current is just 3volt this type of meter can’t accurately find the brief within the aluminum electrolytic capacitors!
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