To track down noises.
Unplug speaker to be sure its not from there.
Use an old paper towel tube as a stethoscope.
When you get to the area use a plastic tool to lightly probe
around & look for the noise to stop or change. Almost always comes
from the FBT, small transformer or choke or the yoke.
Ticking & buzzing comes from power supply or vert.
High freq noises from horz, pin, HV or switching power supply.
Some sets are noisy by nature.
Dont know why the arc on turn off. Just be sure the dag & CRT
board are well grounded to the main chassis.
BTW will look up that Zenith tomorrow.
73 Zeno
