Unused Sub-Part in Component

This document is no longer available beyond version 4. Information can now be found here: Unused sub-part in component for version 5

This documentation page references Altium NEXUS/NEXUS Client (part of the deployed NEXUS solution), which has been discontinued. All your PCB design, data management and collaboration needs can now be delivered by Altium Designer and a connected Altium 365 Workspace. Check out the FAQs page for more information.


Parent category: Violations Associated with Components

Default report mode:


This violation occurs when a part of a multi-part component instance has not been used within the design. For example, three out of four parts for an instance of a 74HC32 component may have been placed and wired but the fourth has not.


If compiler errors and warnings are enabled for display on the schematic (enabled on the Schematic - Compiler page of the Preferences dialog), an offending object will display a colored squiggle beneath it. Hovering over the object will display a pop-up hint that summarizes the violation.A notification is also displayed in the Messages panel in the following format:

Component <Identifier> has unused sub-part (<PartNumber>)


  • Identifier is the parent component, represented using the format Designator Library Reference (e.g., U11 74HC32)
  • PartNumber is an integer used to indicate which specific part is not being used (e.g., 1 represents part A, 2 represents part B, and so on).

Recommendation for Resolution

Place the unused part and connect its inputs to ground. To ensure the same root designator, copy an existing part for that component's instance and, after pasting, increment its part number accordingly.


  • Object hints will only appear provided the Enable Connectivity Insight option is enabled on the System - Design Insight page of the Preferences dialog. Use the controls associated with the Object Hints entry in the Connectivity Insight Options region of the page to determine the launch style for such hints (Mouse Hover and/or Alt+Double Click). 
If you find an issue, select the text/image and pressCtrl + Enterto send us your feedback.