As everyone stated this is very bad because it is a critical part of the device’s function. The first thing I would do is check the deadline because I need to see how much time I have left to see what I can do. For starter find other test that would be able to reduce and replace other test that was scheduled so that the team can go back to R&D to fix the issue. We can also two team, one team run test/other phase that does not need full device while the other team fix the device. The team needs to work as twice as hard. There could be two options that could happen if we don’t complete in time which is the customer ending the project or extending the time, this will cost a lot of money and the company reputation will be affected badly.