unconnected-component

A component appears on no net (none of its pins land on any signal).

Remedy

Wire the part into the circuit it belongs to, or delete it from the schematic if it is left over from an earlier revision. Placed and unwired is neither.

What it means

A component whose pins land on no net at all. It is placed but wired to nothing.

Why engineers want it

Parts get dropped onto a sheet and left unwired during a work in progress, or a block gets deleted and one part survives. The part then ships in the BOM and gets placed on the board while doing nothing.

Impact

Either a real missing connection (the part was supposed to be in the circuit) or wasted cost and board area. Both are worth surfacing.

Flagged: R9 with no pin on any net; fine: U1 with pins wired to nets

Section-aware

Connections key on ref_des, and the IR groups all of a physical part’s sections under one ref_des (WS1-001), so a part counts as connected if any section’s pin lands on a net. A multi-gate IC with one gate wired is connected.

Query structure

select the components not present in the connected-ref set.

select C in components where ref_des(C) != "" and not on_net(C)

Reads: on_net (the connected-ref projection). Tier R (a traverse of every net’s members builds the set the select tests against).