The last article I knew about the decomposition of the electrolytic condenser under load. In this article I will talk about high-voltage resin coated ceramic plate capacitors. A computer monitor is often used on the screen voltage (G2) line on the crt card. If this fails, it may result in a faulty or intermittent raster, bright and sometimes unseen.
Setting the flyback transformer screen control does not solve this problem. The problem can be distinguished by faulty flight or G2 line on the CRT card. Remove the G2 wire from the circuit and measure the screen voltage with a digital multimeter – it must have constant voltage (does not change). If the voltage is not stable, suspect the flight. If this is OK, monitor the screen voltage circuit. Generally, this circuit consists only of resistors and capacitors. Sometimes a broken crt slot can cause this type of problem too!
Many times a tech can not solve this intermittent or non-display problem because digital capacitance and ohmmeter are OK for condensers. The screen voltage line capacitors are generally 102,103 and 472 1kv-2kv. The capacitors were "missing" because the technician can not solve the problem unless it replaces the capacitor. An intermittent capacitor runs the screen voltage causing the display problem
As mentioned earlier, a 12 volt ohmmeter and a digital capacity of 3 volts can not accurately check the capacitor, which is 1-2 kilowatts.
If there is an analog insulator or meter, the panel will shortcut when a certain voltage is pumped to check the high voltage capacitor. The selectable tensions depend on the brand or model purchased. Some range from 50v to 1000v and some are in the range of 100V to 500V. Optional whether or not it is. If so, then this is an additional benefit for you. Another option with which to replace suspect capacitors. In my country you can get one for less than $ 150 or you can hire a used unit from eBay.
As for me, check the small blue resin-coated ceramic dial capacitor with capacitor code 104 50v, plus digital capacitance meter, to set the value to an analogue meter for 10 KΩ which have a 12V output for this type of capacitor check. Many times the bad, intermittent capacitor turns out. You will be impressed that the capacitance meter checks the analog multimeter for OK, but briefly analyzes it.
There are analog multimeters in the market that are in the 100-kΩ range. If you open the cover, you will not see the 9v battery that only the 2 1.5v batteries will see. This type of meter can not accurately recognize the short circuit in the condenser because the output voltage was only 3!
For those who are participating in the repair monitor, you agree with me to check the flyback internal capacity – often you get the correct 2.7nf value with the digital capacitance meter, but when you turn on the monitor, you will hear a tick tick "sound from the flyback. This is because the condenser descends under load. If you have not done anything with the kickback, the internal capacity will gradually be short and you need to renew the flyback.