Siemens Arcadis Avantic: power distribution board cuts the PC at startup
What happened
At startup the power distribution board switched off the Celsius PC: the two green Site and Kusv LEDs on the board went out and a SP indication lit at D22. The PC itself ran normally from a wall outlet, and with no PC connected the board reported no fault.
What was checked
- Ran the distribution board without the PC connected — no fault appeared, which pointed away from the board itself.
- Clarified whether the unit starts from the power button or comes up by itself as soon as mains is applied.
- Reviewed the BIOS settings, which had dropped to defaults after the on-board battery went flat.
Cause
The BIOS battery had discharged and the settings fell back to defaults, so the PC no longer started automatically the way the distribution board expected; the board flagged SP and cut the PC's supply. A first attempt to load the configuration from another unit did not restore correct autostart.
What was done
The engineers reset the BIOS again and re-entered the full configuration. They believe a BIOS option of the 'restore power after mains loss' type had to be enabled; after that the unit started normally. Reported in the case as solved.
Safety
Before working near the power distribution board, isolate the unit from the mains and allow internal capacitors to discharge; after the repair, check protective earth and carry out the electrical safety test before returning the C-arm to clinical use.
Lesson: A PC shut down by the power distribution board at startup is not necessarily a failed board — when autostart behaviour suddenly changes, check the CMOS battery and BIOS power settings first.
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.