No audio when capturing with quicktime 10.2

Typically I use a Sony DSR-40 or my Canon XL2 as a source for miniDV tapes and Quicktime 10.4 to capture on my Mac Mini (late 2012) with OS X Yosemite 10.10.2. Recently, the video is capturing fine but usually, not always, there's no audio on the captured file. While I'm importing, the QT audio meter is moving properly like it's monitoring the audio.

I thought about uninstalling and reinstalling QT but saw posts that say it's "a structure embedded in the in the platform's operating system. To remove/replace it, you would have to delete/reinstall the entire operating system."

I'm forced to use iMovie for capturing, not as good as QT used to be working for me.

Any suggestions?

Thanks!

Processor: 2.3 GHz Intel Core i7

Memory: 16 GB 1600 MHz DDR3