As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 2434 (SEA-HLN) DIVERTED TO GEG FOR F/O ARCDU (NR 2) WENT BLANK IN CRUISE TRIED TO RECYCLE POWER. NO HELP. REMOVED & REPLACED NR 2 ARCDU IAW TASK 23-81-01 PGS 401-406, OPS CHECK GOOD IAW TASK 23-81-01-710-801. RETURNED TO SERVICE.