INFICON Cool Drawer Single Sensor - Manual (Page 42)

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Cool Drawer Single and Dual Sensors Operating Manual
A very useful tool for rapidly evaluating the cause of a persistent "Crystal Fail" is
the test crystal, which is included with each non-modelock oscillator package, this
tool utilizes a packaged crystal at 5.5 MHz and a connector that allows the direct
connection to BNC cables.
The test crystal provides a known "good" monitor crystal that provides a fast means
of isolating sensor problems.
CAUTION
The test crystal is designed as a diagnostic tool, and is
not intended for use in vacuum.
4.1.2 Diagnostic Procedures
The following diagnostic procedures employ the test crystal and DMM to analyze a
constant Crystal Fail message. The symptom is a Crystal Fail message that is
displayed by the deposition controller even after the monitor crystal has been
replaced with a new “good” monitor crystal.
4.1.2.1 Measurement System Diagnostic Procedure
1 Remove the 15.2 cm (6 in.) BNC cable from the feedthrough.
2 Connect the test crystal to the BNC cable.

If the Crystal Fail message disappears after approximately five seconds,
the measurement system is working properly. Reinstall the BNC cable to
the feedthrough. Go to
section 4.1.2.2 .
 If the Crystal Fail message remains, continue at step 3.
3 Disconnect the BNC cable from the oscillator and from the test crystal.
4 Visually inspect the BNC cable to verify that the center pins are seated properly.
5 Use a DMM to verify the electrical connections on the BNC cable, refer to
section 4.1.1 .
 There must be continuity between the center pins.
 There must be isolation between the center pins and the connector shield.
 There must be continuity between the connector shields.
Replace the BNC cable if it is defective and repeat step 2 of this procedure.
6 If the BNC cable is not defective, reconnect it to the oscillator and the test
crystal. If the Crystal Fail message remains, contact INFICON (refer to
section
1.3 on page 1-3 ).