49
Troubleshooting
4000 MiD® Instructions, V6695
Symptom
Possible Cause
Remedy
Severe fluctuations in the
spray current, especially
when spraying a solution
with a high aqueous con-
tent.
There is an electrical
short within the spray-
chip 200.
Reduce the spraychip tip
voltage
Stop the sample flow and
increase the nebuliser
gas flow for five minutes.
Restart sample flow.
Change the spraychip
200 (see chapter 8.2 on
page 33).
Spray current fluctuations
increase under fixed condi-
tions.
Capillary tip may be dull
or clogged.
Replace the spraychip
200 (see chapter 8.2 on
page 33).
A leak in the tubing
Check all fluidic connec-
tions.
Ions are in the wrong m/z
position.
System is not calibrated,
or has lost its calibration.
Follow the procedure to
calibrate the MiD (see
chapter 7.1 on page 30).
Base pressure is too high,
or there is insufficient va-
cuum in the Ion Guide and
Analytical chambers
O-rings may be leaking
Contact KNAUER.
Vacuum pump exhaust
tubing is restricted or
blocked.
Ensure that the tubing
is free from any restricti-
ons.
Vacuum pumps may re-
quire replacement.
Contact KNAUER.
