Bio-Rad PDS-1000 / He™ and Hepta™ Systems - Manual (Page 41)

6.3 Excessive Gas Usage
Probable Cause Action
1. Leaking helium fitting in the system Isolate the components from the He cylinder to the
solenoid assembly by completely closing the metering
valve (turning the knob counterclockwise until it
stops.) Ensure that the regulator gauge maintains
pressure over time. “Soap Test” the fittings by
spraying a film of soapy water at the site of the fit-
tings and looking for bubble formation. Tighten any
fittings that appear to leak.
Remember to close main cylinder valve of helium
tank when not in use.
2. Damaged sealing edge on Gas Replace Gas Acceleration Tube.
Acceleration Tube (scratch or
dent in metal).
6.4 Chamber Will Not Hold Vacuum
Probable Cause Action
1. Door gasket does not seal Test the door gasket (the large rubber O-ring around
the interior perimeter of the bombardment chamber
door) by spraying the outer edge of the closed door
with soapy water while attempting to hold a vacuum.
If the soap bubbles, replace O-ring.
2. Vacuum connection at the back of the Check for leakage (poorly fitting components)
bombardment chamber is not sealed from the clamp assembly located at the rear of the
unit.
6.5 Sample Damage from Gas Pressure Wave
Probable Cause Action
1. Macrocarrier not inserted Examine and replace
2. Microcarrier Launch Assembly not Examine and replace
inserted into bombardment chamber
3. Incorrect sample shelf position Reposition
4. Stopping screen absent, improperly Examine and replace
positioned or fails to function within
the Microcarrier Launch Assembly
5. Incorrect assembly of Microcarrier Examine and reassemble
Launch Assembly components
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