GE LightSpeed: patient table fully lowered and will not raise
What happened
The patient table had travelled to its full lower limit and would not raise. Table buttons on the gantry were inactive, while table power was present and the table still responded to the foot pedal, as reported in the case.
What was checked
- Checked table power supply — present in this case.
- Confirmed the table moved from the foot pedal, so the drive and basic power path were alive.
- Inspected the tape switch ribbons along the table edges for damage.
- Reviewed the error logs; no specific codes were reported in the case.
Cause
The engineers found the most probable cause was a damaged tape switch (safety edge ribbon) on the table: an open protection circuit blocked the raise command and disabled the gantry buttons. The cause was not finally confirmed in this case.
The cause is probable and was not fully confirmed.
What was done
The table was first raised using a procedure from the manufacturer's service documentation, done by authorised personnel. The damaged tape switch ribbons were then checked and replaced, after which normal raise control was expected to return; the outcome was probable, not fully verified.
Safety
The tape switch is a pinch and crush protection: keep the area under and around the table clear of hands, cables and patients during any service raise, and do not return the table to clinical use until this protection is restored and verified.
Lesson: When a table will not raise but power and the drive are fine, suspect the safety strip circuit first — an open protection can lock out all normal raise controls.
Covered in the course: CT 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.