It should be clear that for Zakat being obligatory, cash or intention of trading/business with goods is necessary. Therefore, in the above mentioned scenario, Zakat is not mandatory on machines that are not in use. However, if the machines were brought with the intention of business/trading, then zakat will be obligatory after one year, on the income generated from those machines given that it reaches the value of Nisaab
ALLAH Almighty knows best
DARULIFTA AL-IKHLAS, Karachi