Testing the Monitor CRT Yoke Coils
CRT yoke coils consists of two coils (windings) ie; the horizontal and the vertical yoke coils. It is easy to check on the horizontal yoke coil. Simply measure the coil with Dick smith flyback tester and it should rings 4-5 bars and above. If you get 1-2 bars and the LED don’t lit then it is either had developed partial or complete short between windings. Do not check it with normal multimeters as shorted yoke coil the meters also show good reading! Vertical yoke coil rarely become defective and the dick smith flyback tester can’t test it. Make sure that it has ohms range from between 3 to about 9 ohms . If you get a measurement of 100 + ohms then most likely the vertical coil have problem and need replacement!