An engineering change list that removes and re-adds a familiar component may indicate a broken identity link rather than an intended hardware replacement. Pause and inspect the mapping before executing the operation. Recreating the footprint can disturb placement and routing while concealing the original mismatch.
Altium’s synchronization documentation explains that schematic and PCB components are linked through unique identifiers. It also notes that copying or cutting and pasting schematic components renews identifiers. A matching visible designator therefore does not prove that the underlying link is intact.
Identify the intended pair
Compare the schematic instance and PCB footprint using designator, device identity, pin numbers, net membership, and location in the circuit. Do not repair a link solely because both objects currently display the same reference. Reannotation or copied sheets can make that shortcut misleading.
Retain a recoverable design revision before changing links. Record which unmatched objects are expected to represent the same physical component and which are genuinely new or removed. This makes the proposed repair reviewable instead of turning it into a sequence of trial-and-error updates.
Inspect the mapping evidence
| Evidence | Use |
|---|---|
| Unique identifier | Understand the existing synchronization link |
| Reference designator | Locate the visible design instance |
| Pin-to-net assignments | Confirm the intended electrical role |
| Footprint and package | Check physical compatibility of the paired objects |
Pay particular attention to repeated channels. Several components can have similar values and connectivity patterns while belonging to different channel instances. Use the compiled hierarchy or another unambiguous channel identity when reviewing those mappings. Cross-probe a distinctive connection in each channel and inspect its destination on the board; two repeated blocks can look nearly identical while representing different physical interfaces.
Re-run the proposed change
- Repair only the justified component links.
- Regenerate the synchronization comparison.
- Confirm that unintended removals and additions disappeared.
- Review all remaining changes on their own merits.
- Validate the updated schematic and PCB together.
A repaired identifier does not prove that the two objects have identical content. The next comparison may correctly propose parameter, footprint, or connectivity updates. Evaluate those differences instead of suppressing them simply because the component pair is now recognized.
Document the operation that caused the link loss where known. When reorganizing a schematic, use a supported refactoring method that preserves the intended identity rather than repeatedly repairing the result afterward. The useful final state is a stable correspondence between logical and physical components, with synchronization changes that reflect actual engineering edits.
Move from reading to a build-ready project
Use the fabrication and assembly checklists to prepare drawings, production files and test requirements.
Open the DFM checklist