Waters 2996, Operator'S Manual

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User-Initiated Diagnostics 17
2
2.2 User-Initiated Diagnostics
Note: The system administrator can restrict access to the 2996 Detector diagnostics by
disabling user access to Run Samples. For details, refer to the Millennium
32
Help .
There are two types of user-initiated PDA diagnostic tests:
• Internal Tests – Tests run by the instrument firmware that help you determine the
source of a malfunction. These tests do not require connections to external devices.
• Interactive Tests – Tests that check analog output and event input/output signal
communications between the detector and connected external devices. These tests
require connections to pump flow and/or test equipment.
You can run all user-initiated diagnostics from Run Samples in the Millennium
32
software.
For more information on Run Samples and PDA diagnostics, refer to
the
Millennium
32
Help.
Change in reference
spectrum Mobile phase contains
gas or is contaminated Prepare fresh mobile phase and degas
thoroughly.
Air bubbles trapped in
flow cell Reseat and check alignment of flow
cell.
Flush the flow cell, or apply slight
backpressure on the detector waste
outlet.
To prevent air bubbles, check that there
is a 1- to 2-foot (30- to 60-cm) length
of 0.009-inch (0.23-mm) ID tubing
connected to the detector waste outlet.
Solvent in drain line Leak from flow cell
gasket Rebuild flow cell with a new gasket
(Section 3.1.3, Disassembling and
Cleaning the Flow Cell).
Leak from flow cell
fittings Check fittings for overtightening or
undertightening, and replace fittings if
necessary.
Table 2-1 2996 Detector Troubleshooting (Continued)
Symptom Possible Cause Corrective Action