An older ASUS homebuilt which has started acting up in the following way. The problem only occurs when I unplug the computer from the wall (usually to avoid lightning strikes) and am gone for a few days. The computer refuses to respond at all after replugging. Have in the past restored operability by plugging and unplugging power cord, switching PS on and off and unplugging and replugging the SSD C drive. Could a bad CMOS be causing this?