Problem: Chamber A cannot backfill to 70 Torr

[EE]

Ch. A failed initializing pressure subsystem....Other alarms on the
system were:
- Ch. A pressure control valve failed to close
- Ch. A press. cont. valve never reached home in minus direction
- Ch. A reduced pressure stepper failed

[EE]

This alarm was caused by a dirty throttle. We removed the throttle
valve and cleaned it by soaking it DI water. Placed a dummy throttle
valve in placed of the dirty one and pumped down the foreline as soon
as possible in order to minimize exposing the line to air. Performed
a throttle valve calibration after re-installing the clean valve.