The number of revolutions of the turbomolecular pump 2 (Small Pump) went below the limit (In Standby mode).
Check the number of revolutions and the current of the turbomolecular pump 2, vacuum pressure (AN), vacuum pressure (IF/BK), and power voltage. The following causes are inferred.
An increase in the vacuum pressure.
The connector of the turbomolecular pump came off.
Faulty turbomolecular pump power.
Faulty turbomolecular pump or turbomolecular pump controller.
There is a fault in the Connection PCA.
There is a fault in the QQQ System I/O PCA