GE Proteus XR/i: table and column movements locked, tube drifts freely
What happened
Reported in the case: table and column movements stayed locked and did not release when the pedal/button was pressed, while the tube assembly drifted back and forth on its own, with no button pressed.
What was checked
- Pulled up the service documentation and inspected the motor control board in the table base
- Checked the column bearings for wear and play
Cause
The engineers found a cold solder joint on the legs of the diode bridge on the board in the table base, where the motor driver sits; separately, the column bearings were worn out.
What was done
Re-soldering the cold joint on the diode bridge legs restored control of the table and tube movements; replacing the worn column bearings restored normal column travel. The case was resolved.
Safety
Isolate the system from the mains and allow capacitors to discharge before soldering on the base board, and verify brakes, movement controls and electrical safety before the system returns to use.
Lesson: One cold joint on a rectifier can mimic several unrelated faults — check the power stage on the driver board before blaming motors, mechanics or software.
Covered in the course: X-ray 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.