I received a couple of the later miners (which have individual heat-sinks) where the heat-sinks were loose in the case (they'd fallen off in shipping, one of the boxes had clearly been dropped), and Inno sorted the problem out straight away once I'd sent them back, sending me new hashboards. Time Zone and language barriers aside, they are always very helpful when I've dealt with them.

There's a critical piece of information missing from your post, what kind of power supply are you using? These Inno boards are well engineered and extremely robust, so if they're burnt out it suggests there may be a problem with either the boards circuitry or the power supply, and Inno are very honest in my experience so I personally think they'd say if they had found a problem with the boards voltage regulation.

Might be an idea to check your PSU before connecting it up again.