JACK A4B-A/C Err-11: Fix Needle Position Synchronizer Fault
Exact model: JACK A4B-A/C
Safety: Disconnect mains before clearing thread or checking motor/solenoid connections.
A.
Start with the accessible checks
What this suggests: Err-11 is linked in the researched control family to needle-position synchronization.
What to do
- Unplug, check the handwheel/needle bar for obstruction and inspect the accessible synchronizer mounting or cable routing per the controller manual.
- Restore a loose sensor connector or displaced sensor bracket without changing undocumented adjustment angles.
Still not fixed? Continue to the next check.
↑ Back to the repair pathsB.
If the problem remains after the first checks
What this suggests: A loose shaft-position sensor or improperly seated feedback connector can give wrong needle-up/needle-down registration.
What to do
- If wiring is sound and Err-11 persists, qualified service must check the matching synchronizer and replace/align the confirmed faulty part using the correct board's setup procedure.
Confirm the repair
The machine parks at the intended needle position consistently and no Err-11 appears after normal stop/start cycles.