To fix the A4 the 2 hashing boards must be Re-Flashed with a special Jig that re-programs the hashing boards. These Jigs are very expensive so Inno has shipped one Jig to forum member Longsnowfm. But there is only one Jig that needs to fix all of the A4 miners. So the group here is deciding what is the best way to get all miners fixed with just one Jig.. Hope that helps