I'm sure they should be repairable too. I'm surprised they don't do an exchange when you buy a replacement for a failed card. They're not far on a grand a piece to replace.
Generally I loose the entire card at a similar time, so I loose control of most of the aspects across all the inputs and get white noise across all channels as well. The one that I'm looking to replace at the moment has either a completely dead channel or white noise being outputted down the channel. I replaced 2 before Christmas with the same faults. I'll have to go and have a look as we've just been avoiding using the card all together and cant fully remember what the full symptoms are, but I do know its globally across the card.
If you move the card to a different slot in the rack the issues/symptoms follow. Its in an install so the racks never moved, and the patch very rarely changes.