In the two instances, which occured approx 2 months apart, the system appeared to work normally, but when using IQwic with it (the PC running IQwic is not running permanently), the metering and mute status of some inputs and outputs was incorrect. In our case, Main output B and some of the aux outputs was wrong.
We went through the system, component by component, thinking it must be elsewhere in the system. We finally concluded it was the 8810C, so I power-cycled it, and all was well again.
Our only theory at present, is that it may be suffering from any mains voltage irregularities (under/over-voltages, brownouts etc). We are therefore looking at installing a line conditioner or UPS to see if that prevents this re-occurring.
Curiously, we had a client at work who had an IQ-USM 810 "lose" its three presets. The client was convinced that it was power related, as they have very high voltages (up to 260V) present in that part of Scotland (measured UK voltage is 240V in most places, not 230V as most non-UK residents often think. Not truly unified with Europe yet, I'm afraid
Working for a distributor, I see many products with switch mode power supplies suffer problems of various types. This is not necessarily a criticism of them, rather an observation, that perhaps more research needs to go into their specification, and tests on long-term real world performance. I think manufacturer's reputations can often suffer as a result of buying in an OEM module.











