Siemens Symphony MRI: patient table overshoots horizontal position
What happened
As reported in the case, the patient table would not stop at the horizontal position and travelled past it; error 134 was flashing on the display.
What was checked
- The error appeared only after the table reached the transition point from the vertical position, which pointed to the limit switch at that point rather than to the drive or the control board.
- Inspected the limit microswitch at the transition point and checked the position of its actuator lever against the PTFE shoe on the table.
Cause
The actuator lever of the limit microswitch was broken off, so the switch no longer signalled the transition point and the table kept travelling past the horizontal position.
What was done
As a temporary measure the engineers bent the remaining part of the lever so the PTFE shoe actuates the switch again, and the table began stopping at the horizontal position. Moving a microswitch from a less critical (intermediate) position was suggested as an interim option, since a new switch is often not in stock; the final repair should follow the manufacturer's service documentation.
Safety
Limit switches define where the patient table stops: after any switch repair or adjustment, run the table through its full travel range empty, confirm every stop and the emergency stop work, and do not return the table to patient use until they do.
Lesson: When a fault shows up only at the end of travel, suspect the limit switch at that point — a broken actuator lever is a typical failure, and a switch borrowed from a less critical position can bridge you to the new part.
Covered in the course: MRI Service — Level 2: Fault-Finding →
Written from an anonymised case shared by service engineers. It is not a manufacturer instruction and grants no authorisation. Independent note; names are trademarks of their owners.