Concord and Savaria merged a few years ago and I've found that Concord's tech staff is extremely helpful. Their number is (800)-265-5416 or local (519)-681-3311.

From my experience, the batteries (which should be something like 2, 12v 7ah and readily available) can fade over time and cause issues like yours. Also, the charging mechanism, which is the small green circuit board, may not be emitting the 24v necessary to operate the door locks and call stations correctly.