Radiometer ABL700/ABL800: Analyzer fails to start at power-on
What happened
As reported in the case, the analyzer would not start and produced a fault within the first minute after switching on.
What was checked
- Check the status LEDs of the SMD fuses behind the rear panel first — in this case they indicated that the supply voltages were present.
- With the covers off, inspect the silver-plated fuse contacts for oxidation, and while inside, reseat and check the ribbon cables as well.
Cause
The engineers found oxidation on two silver-plated SMD fuses behind the rear panel; the oxide layer gave a poor contact, which was enough to trip a fault at startup.
What was done
The oxidized fuse contacts were cleaned, and after powering back on the analyzer started and worked normally. The case was reported as solved.
Safety
Disconnect the analyzer from mains and let the power supply discharge before working behind the rear panel, and run the electrical safety test before returning the instrument to use.
Lesson: Contact quality counts as a real fault: oxidized fuse contacts can mimic a dead power board, so check simple connections before suspecting electronics.
Covered in the course: Lab Analyser 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.