After an NE40E-X16 was powered on, the alarm indicators for its four fans became on.
1. Replaced one fan module, its alarm indicator was still on.2. Checked fan configurations. The fans monitored their PEMs. It was suspected that the problem occurred because not all PEMs were used. After all PEMs were powered, the indicators become off.
NE40E-X uses area-based power supplies. Each area has a fan. When not all PEMs were powered, the fan alarm indicators became on.