** brand new Daewoo microwave ... the touch pad no longer works. The microwave is plugged in, but you can't do anything on it? **
Is anything working on the unit?
If nothing at all is working, the internal fuse may have blown. If so, since it is "brand new" it should be under warranty in which case it should be taken to a local Daewoo factory service depot to find the cause and have it corrected along with replacing the fuse.
If just the control is not functioning and other things (lights, etc.) do work, there may be some sort of 'child lockout' which is engaged. Check the owner's manual. Otherwise there is likely a problem in the unit in which case it should be taken to a local Daewoo factory service depot to find the cause since it should be under warranty.