There are different types of troubles occurs due to fault in the power supply section. Some of them are given below:
1. No B+ Voltage:
Troubles that can cause no B+ voltage include an open diode in rectifier circuit, an open filter choke or resistor and shorted filter capacitor. The capacitor becomes open or practically open with reduced capacitance. As a result the poor regulation of the B+ voltage for the load & excessive hum.
2. Blooming:
This term describes a picture that increases in size, defocusing in white areas as the brightness is increased. A common cause of blooming is a weak high voltage rectifier, which has excessive internal resistance.
