Siemens Magnetom Aera 1.5T: GPA fault after mains voltage surges
What happened
After mains voltage surges the scanner reported a GPA fault that survived restarts. In Test Tools fast mode the fault indication went away, but scanning stayed blocked with the magnet shown as crossed out, while the gradient and modulator tests passed.
What was checked
- Restarted the system — the GPA fault kept coming back
- Ran Test Tools in fast mode — the fault flag dropped, but the magnet stayed crossed out and scanning remained blocked
- Ran the gradient and modulator tests — both passed
- Checked the communication state between the modulator and the gradient chain
- Confirmed VLM presence at the magnet
- Asked about the UPS, its batteries and the quality of the mains supply after the surges
Cause
The engineers found a software failure, not hardware damage: after the power event several processes did not start, so there was no communication between the modulator and the gradients, and the system reported it as a GPA fault.
What was done
No hardware was replaced. The fix was a procedure from the manufacturer's service documentation, done by authorised personnel: the software image was reinstalled, after which the system started cleanly and scanning became available again. Reported outcome: solved.
Safety
A power event that corrupts software can also stress the power chain, so check the UPS, its batteries and the mains supply, and complete the manufacturer's electrical safety and system tests before returning the scanner to clinical use; the gradient amplifier cabinet stores lethal energy, so isolate, allow capacitors to discharge and follow the service documentation before opening it.
Lesson: A fault flag can point away from the hardware: if subsystem tests pass but the system stays locked out after a power event, suspect startup processes and software state before ordering parts.
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.