This demonstration guide answers one field question about welded line inside a hot head or a failed tap mechanism. Measurements come before parts, and the notes are not a generic equipment FAQ.
Diagnose before replacing parts
Start with head disassembly and remaining line coil. That reading separates welded line inside a hot head or a failed tap mechanism from adjacent faults that share the same complaint.
If the measurement is out of spec, treat the trimmer head as the primary path. If it is in spec, do not replace the trimmer head just to complete a parts list.
Repair the failed system
The usual correction is the trimmer head, installed to the documented spec for this complaint.
A demonstration shop records the finding so the next technician is not repeating a guess about welded line inside a hot head or a failed tap mechanism.
Stop before you make it worse
Do not forcing the head against concrete to "unstick" it. That shortcut hides the original measurement and creates a second failure.
If the machine still fails after the trimmer head is corrected, convert the visit to a broader diagnosis rather than stacking parts.
Written and published by Ridgeline Small Engine.