Gun trigger input is active (AFS or Integration) and no C meter pulses are detected during the dose time selected.
Fully trigger the gun.
Increase flow rate.
Increase the dose time setting.
See E-3: RATIO HIGH ALARM and E-4: RATIO LOW ALARM.
Turn on the supply pump.
Check the air lines for leaks and repair.
Clean or replace air flow switch.
Verify condition of fuse and replace if necessary. See Repair-Parts manual.