Power Supply  To hold the high voltage of the monitor constant at all working conditions is very extravagant.       A minor stabilisation appears especially during the picture brightness is changing from black to white. If the monitor has a minor stabilisation, the picture will be as shown left. Bright picture parts increase the width. Please observe the effects on the monitor during fast changes between bright and dark picture through the help of the test patterns. Bad stabilisation of the high voltage leads to continuing changes of picture width, the so called 'pumping' of the picture.