Fantastic! Glad it's back!

I am sad to report that my replacment ZDAC-1 has just also died in the same manner that the first one did.This leads me to conclude that the problem must be ME.
The only thing that I can figure is that my computer is hitting the ZDAC with something that isn't right. I can't imagine that two DAC's would die in the same manner without some sort of outside influence.
Both times that this has happened is when I had been playing a file off of my Dell computer, not my usual Gateway. When I unplug the USB cable and switch the ZDAC back over to coax to listen to my Ipod/Wadia combo, nothing plays.
I'm a little depressed right now, I guess that I will start looking for some kind of replacment DAC. I can't imagine that Decware would give me another one to blow up.

Sorry this is up Donnie. I agree with Lon. I would check with Steve.

Have you tried unplugging the USB and then plugging it back in back of the DAC to see if DAC connects to the computer. Or cut off the ZDAC for a while, then power up again, connect the USB, and restart the computer with the DAC plugged in. It may be that the DAC Digital in is somehow confused? Also, once mine stopped working in this way and I went to the audio out on the MAC and found that, for some unknown reason, the DAC and Mac had not hooked up even though they had been playing together the days before. The Mac Audio out was still set on internal audio. I changed it to the USB and all was well. Worth a try anyway.

Yay heavy and a bottle of bread Donnie! Yeah, the ZDAC-1 is an awesome DAC, it's so sad that it's not available any longer. I had to spend many multiples of the price to really be wowed by another DAC (the PS Audio PerfectWave I'm using now). Glad yours is up and running again. Fingers crossed it keeps on working.

I always left mine on. I don't do computer audio so I have no experience of it not working with a computer, and it always worked for me. The only times I thought I had a problem was in fact operator error. . . not having the switches in the right configuration but thinking I did. I confess that happened. . . more than twice. (I had the unit facing backwards, which didn't help).

Great! Here's hoping that it keeps on keepin' on!

Well it didn't come back up this morning. I shouldn't have shut it off last night.
Thinking back on how it has went down before, I came to the thought that it always failed after the power was shut off. Once the power went out in my 'hood while I was at work and the ZDAC didn't come back up when I got back home. I'm going to experiment with shutting it off and on. If that doesn't work I guess that I will pack it up and send it back to E. Peoria. Damn, I was really liking how it sounded, it added a lot of punch to everything.
At one time I thought that it was something that I or my system was doing that  caused the problem but since then I've stuck another DAC in it's place with no troubles at all. Maybe the third time is the charm.
Dan,
Heat maybe, but it stays a pretty constant temp down here in my bunker, I'm 4' underground and it stays pretty close to 70 all of the time.
I have "Tapped" the DAC several times with no luck. Of course always remember that hitting a inanimate object only hurts yourself, and makes you look a fool to everyone else.
A power supply problem would be over my head, unless you want to design a machine to make it. As far as I can determine, electricity works off of smoke, if you let smoke out of something it never works again. When you go by a powerplant there is always smoke coming out of a chimney, that means excess power is being made. Simple.