aq5000/5001 Bulletins:

Reported Symptom(s):
Instrument loses memory after collecting data under AC power.

Cause:
Faulty AC power cord results in AC power intermittently or never being supplied to instrument.  If this occurs power automatically is drawn from the internal batteries and, if enough time elapses under this condition, the internal batteries are drained beyond their ability to retain memory.

Solution:
Contact the factory for a replacement AC power adapter.