Yes, reseating the connectors will work in the short term. Permanent fix is to replace those IDC connectors with LOCKING connectors and trifurcon crimp contacts. Also replace the solder in the optos with leaded stuff. Don't bother with zip ties, it'll just come back with the amount of vibration in the trough. We've had ACDC Prem and ST Pro out on route with these issues, and have found this to take care of the problems.