No sound from cdp.

I have a Marantz cd5001 I've been using with a CA Dacmagic. Recently, on occasion, I'll get no sound. I have sound from my computer, and from my tuner as well. When I click to digital 1 on my dac, I notice sometimes there's no signal coming from my cdp. Of course I also have no sound. If I take things apart, or shut it down completely, it usually comes back on. This is getting frustrating though. So I'm asking for some advice. New cdp (transport)? Or do I need to look at something else? Any and all responses are appreciated.
Have you tried bypassing the Dac and just use the Marantz. Maybe the DAC is the problem.
Thanks for your response.I have my music files from my computer running through my dac. They play just fine. I have tried bypassing the dac, and my cdp plays just fine. However when I hook it back up to my dac, it plays fine then. I just had this happen again moments ago. I turned off all my gear, waited for about a minute, turned everything back on and BAM...I had tunes. This is happening more frequently and frankly I'm not going to constantly turn my stuff on and off to jam. I'm thinking time for something new..
Sounds like the DAC is not "locking" onto the output from the transport. Maybe the Marantz is shuting off the digital output after a period of time. Turning off , then back on, resets the digital out. Could also be that the transport is outputing a signal, but the DAC isn't locking on. Have you tried a different input on the DAC from the transport? You'll need to troubleshoot a little further.
Try a different digital cable from the CDP to the DAC. If you do not have one just use an analog ic or a video coax cable.
Good points as usual, that's why I post here. I'll do a little more troubleshooting. I might just bypass the dac for a few days. I only bought it to play the files from my computer anyway.
It could be the DAC's input switch, especially suspect if it drops out while playing. Try cycling thru the DAC's inputs a few times to get it to cooperate before going the unplug route.
Sometimes just turning off the cdp and turning it back on will work. Sometimes I have to turn everything off to reset it. It never does it while playing. I'll listen to a cd and it may play fine. Take that disc out and put another in and it may not play it. The cd doesn't matter, I've experimented with that already.