Philips MicroDose L30: system won't start, only the chiller fan runs
What happened
After assembly the mammography system refused to start up. The only sign of life was the thermochiller fan spinning; no error codes were reported in the case.
What was checked
- All emergency stop buttons and interlocks were first checked for an open safety chain.
- The engineers measured the output voltages of the two power supplies at the bottom of the equipment rack and found both units dead.
Cause
Both rack power supplies were dead, so the control electronics had no power at all, while the chiller ran on its own feed and kept spinning its fan.
The cause is probable and was not fully confirmed.
What was done
The fix reported in the case was to test and replace both failed rack power supplies. The outcome was treated as probable, since the diagnosis relied on symptoms matching a previously seen case, not on direct confirmation.
Safety
Isolate the cabinet from the mains and allow the power supply capacitors to discharge before working inside the rack, and complete the electrical safety checks (protective earth and leakage currents) before returning the system to clinical use.
Lesson: When an assembled system shows almost no signs of life, verify every power supply rail at its source before chasing individual subsystems.
Covered in the course: Mammography 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.