Thank you for suggesting some reasons for the intermittant failure of this DVR.
The mains quality here in the UK is consistenly good. Dips, troughs, brownouts, or spikes rarely occur. Mains surges are equally rare and electrical apparatus designed for use in the EU must be tested and certified as EMC compliant. The test standard does address immunity, a component of which is the mains quality testing.
However, the fault which is consistent to both Avtech DVR's, only occurs when it is executing a command from the remote control, i.e, when selecting 'an event' to playback and view. Unless the button pushing is done slowly, both DVR's would lockup and eventually reset. THe 792 is less prone in that regard.
My two cents diagnosis suggests that the microprocessor doesn't have the horsepower for the job, or at the least, it gets pretty stressed out when it is called up to perform an action!
To sum up the Avtech and I agree with you, it is built for the job as a domestic DVR. But only just fulfils that requirement!!
Rgds,
Graham