Hi @Mitch ,
Cables are definitely the first place to (triple!) check followed by connectors (i.e. look at the pins in the RJ45 socket of both the Qu dSnake and ME dSnake/ACE ports).
If you can’t find anything here, and as your title is ‘Everything connected dropping out’, I would then recommend getting the system down to a bare minimum, so try a ME-1 connected directly to the Qu’s dSnake port, powered by it’s own PSU.
This will give you some idea about whether the issue is at the Qu or ME-U or any expander you might have connected.
If the problem appears to be at the ME-U, then remove/check/reinsert the dSnake/ACE card, as well as connecting via HTTP to check/update firmware ( https://www.allen-heath.com/ahproducts/me-u/#tab5 ).
At which point if you still haven’t found anything, please contact us directly using https://support.allen-heath.com.
Thanks,
Keith.