Here is the scenario. 30 year old mobile home, with older ITS Gould breakers, that some of the breakers have no power, and some do. I tested the main breaker, with all the breakers off, and found 111 volts on one side, 109 on the other side, roughly 236 volts testing across the breaker, however, if I turn on certain breakers, such as water heater, kitchen, the half of my bedroom that is out, or the dryer, one side of the main drops to zero volts, and, it does not matter what combination of breakers I turn on, the one side of the main goes to zero, so,would that suggest a bad main?