Bucko wrote: That makes sense for an electric motor where the speed of the motor is fixed to the line frequency so dropping the input voltage necessitates a increase in current which can burn out the motor. Never head of that in an electronic circuit though. If nothing else fuses could be used to limit current damage in low voltage situations. Perhaps the diodes mentioned are sacrificial diodes - are they easily replaceable?
Fuses only limit/ protect for overvoltage situations. They do nothing for sensitive components that encounter low voltage outside of their specified range.
These older components can be damaged on either side of the current spectrum. Low or High.
As far as getting into exactly what items or how it happens, suffice it to say the box stops working.
Regards.
Todd.