The problem with an intermittent system can be difficult to isolate. A careful substitution or swapping of components can assist you in locating the problem piece of gear. If, for example, you have an occasional loss of right channel information, start by setting up your rig to record your stereo and swap mics to see if the problem follows the microphone. If you swap left and right mics and the problem changes sides, it's the mic. If not, make a note of what you did and swap the next thing. Try swapping mic cables, switch sides on the mic preamp, then try swapping preamp to deck cables, run the signal into another deck. Using this simple method of swapping or substitution and careful note taking you can determine which piece of gear in your rig is the problem.