The problem with not doing some preventative stuff on these old machines is that in the event of a power supply failure (IIRC the MZ-80K has +12V, +5V and -5V) you can get overvoltage and cause damage to the chips.
The problem with not doing some preventative stuff on these old machines is that in the event of a power supply failure (IIRC the MZ-80K has +12V, +5V and -5V) you can get overvoltage and cause damage to the chips.