Partial import

I am only getting a small partial import of video when importing from DV tape. Problem is recent (last 3 days). Amount imported varies from several seconds to several minutes. Other than than turning my MacBook off at night and on the next day nothing has changed with the system. I have tried several tapes and repeated tries with the same tape but the problem is solid with the exception of the amount of video transferred. I am using iMovie 10.0.5 and iOS 10.9.5. Any ideas or suggestions?