The invention relates to a
CRT display, especially a method for detecting and activating
kinescope ageing of a
CRT display, the method comprises observing whether a smearing phenomenon is existed when the brightness of the
kinescope is not high, then the brightness and the contrast are increased, under the condition that each pole
voltage of the
kinescope is normal; if the smearing phenomenon is existed, dismounting the casing of the display and pulling out a base of the kinescope, after applying rated
voltage on the filament of the kinescope for 3-5 minutes, connecting a modulating
electrode using a black meter pen of a mechanical
multimeter 1K shift, connecting red, blue and green three electrodes respectively by the red meter pen; when the testing resistance value is between 5K and 10K, applying 8V-9V
voltage on the filament, replacing 110V voltage with a
power supply voltage of the TV set itself, electrifying for 3-8 minutes, reactivating one time after 10 minutes, the kinescope is recovered in normal immediately. The method can not only reduce the maintenance cost, but also simplify the maintenance operation steps.