1149   Error: Vacuum pressure (BK) is too high to keep the turbo on.

As vacuum pressure (IF/BK) exceeds the limit, the turbomolecular pump cannot be kept ON (In Standby mode).

Check the vacuum pressure (IF/BK). The following are the probable causes.

• The vent valve is not closed or the seal is incomplete.
• The cover of the vacuum chamber is not closed or the seal is incomplete.
• The power of the foreline pump is not connected or the breaker is OFF.
• The foreline pump oil level is low or the oil is dirty.
• There is a leak in the gate valve.
• The vacuum tubing has failed (the tubing is off, or a leak is caused by an incomplete seal such as a pin hole or a defective O-ring).
• There is a fault in the Pirani gauge (IF/BK) or the Connection PCA.
• There is a leak in the backing line, between the turbo pump backing port to foreline pump inlet port.