As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 651, CLT-SJU: DURING CLIMB, BOTH VOR'S DEFLECTED BACK AND FORTH FULL SCALE, AND WOULD NOT MAINTAIN BEARING TO ANY STATION. FLIGHT RETURNED TO CLT. MAINTENANCE COULD NOT VERIFY FAULT. CHECKED WITH ALL POWER SOURCES. INSPECTED E&E RACK CONNECTORS. NO FAULTS NOTED. REPLACED BOTH VOR RECEIVERS AS PRECAUTIONARY.