LED Status Indicators

Document created by paolalab Employee on Oct 19, 2020Last modified by paolalab Employee on Nov 16, 2020
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Agilent Support Insights


This Information Applies To: All HPLC modules



The LED Status Indicators are common features for all the HPLC modules. The indicators are located on the top right corner of each module, opposite to the power switch led as shown in Figure 1.


They can vary between six different statuses: Grey (led off), Green, Yellow, Red, flashing Yellow or flashing Red.


The LED Status is very informative on the module performance and can provide important information for troubleshooting.


instrument led status HPLC


Figure 1: Position of LED status indicators and the Power Switch on HPLC modules.




  • Red LED

Error condition.

It indicates that the module has detected an internal problem that will effect the correct operation of the module. Usually, an error condition requires attention (e.g. leak, defective internal components). An error condition always interrupts the analysis. If the error occurs during analysis, it is propagated within the LC system, i.e. a red LED may indicate a problem of a different module. Use the status display of your user interface for finding the root cause/module of the error.


An error code can either pop-up in your CDS software, or can be found in Lab Advisor under the Log & Results panel (as shown in figure 2).

Lab Advisor will also provide information on the error source and suggest solutions.


                    lab advisor log results error code status


Figure 2: Error cause identification using Lab Advisor.


  • Yellow LED

Not-ready condition.

The module is waiting for a specific condition to be reached or completed (for example, immediately after changing a setpoint), or while a self-test procedure is running.

The LED is yellow while the module is initializing, after the initialization process is completed the led normally turns off/grey.

If the yellow color remains for longer than few minutes, it may indicate that the module has an issue trying to reach one of the method setpoints.


  • Green LED

Run mode. A green status indicator, indicates the that module is performing an analysis.


  • Grey LED (led off)

Idle status. This status does not indicate a failure or an error.

When the status indicator is OFF (and Power Switch light is on), the module is in a pre-run condition, and it is ready to begin an analysis.


  • Blinking yellow/red

Resident firmware mode or low lever error mode.

A blinking LED indicates that the module is in resident mode (e.g. during update of main firmware).

A fast blinking LED indicates that the module is in a low-level error mode. In such a case, try to reboot the module or try a cold-start (Forced Cold Start: to solve module initialization issues and software recognition). Then try a firmware update according to the User Manual. If a firmware update does not help, a main board replacement may be required: contact Agilent your local Agilent Service representative for further support.


Learn more on how to operate your Agilent LC System:

LC User manual library on Agilent.com



Keywords: LED, status indicators, error, idle, green, yellow, red, blinking



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