McCormack DNA .5 - No Sound - Help

Hyounessi It's possible your amp is not coming out of protection mode. You might have failed output devices or a defective protection circuit. Some of these units had circuit board issues as well. I would contact Steve...

My DNA 0.5 does not come on anymore. The 4 rail side fuses had gone bad and I replaced them. Also, replaced the power fuse. powering it back on, no light comes on, but I can feel the unit vibrating. Turning off, the unit stops vibrating. Any ideas what can be wrong?

There does seem to be something in the always on suggestion. I don't know beans about circut design or ee, but I had a 0.5 dlx for about a year without any fuse problems, and now I've had a 0.5 rev b running for 2 months without a problem. I do leave em on all the time (and turn my tube pre off).

Ditto to all the above.......I've had an 0.5 Deluxe for a couple years and have had my share of blown fuses.I have found it to be very sensitive to any power surge upon turn on especially if it's been off for a while.It seems that the storage caps can be easily overwhelmed having something to do with the very nature of the DNA design of numerous small caps.The best solution is to just leave it on as this is what McCormack recommends.

I had the same problem as you with my 0.5 Rev. A and Steve talked me through replacing the fuse(super nice guy). He told me to use the Radio Shack fuses(which I did) so I assume they're fine. By the way, I haven't had a problem after 6 months of near constant use. For what it's worth...

Tim

Thanks for your input everyone. I opened the top and sure enough found that one of the 5 amp fuses on the sideboard was blown. I replaced the fuse with one from radio shack and am happily listening to Charles Brown on my DNA .5 as I write this. I guess for now I'll just wait and see if this happens again. In the meantime, is there any reason why the radio shack fuse would not be as good as a fuse from McCormack? Thanks again.

I have a DNA-1 which about 2 years ago suddenly became mono. I replaced the internal fuse and it blew right away (this is a good clue that something is seriously wrong). I then contacted Steve McCormack. I had the unit upgraded at the same time that it was repaired. The output transistors needed replacement. Cost for the repair was $120 and the turnaround time very reasonnable. That has been the only problem in 6 years of ownership. Good luck.

POWERS LOUSY HERE-- MINE BLEW A FUSE INSIDE, PROBABLY BROWN OUT - DID THE YELLOW LAMP THING. HAD MY GUY AT STEREO SHOP LOOK AT IT AND HE REPLACED THE FUSE. SAID WAS THE RIGHT SIZE BUT I SHOULD GET A FUSE FROM THE FACTORY..?? HAS WORKED FINE SINCE REPLACEMENT. LOVE MY AMP!!!

Good response by Bixby. Next step would be to contact Steve McCormack at www.smcaudio.com Steve's a nice guy, and would likely offer suggestions as to how to proceed. Good luck. Craig

Slow down, mine blows fuses almmost regularly. That can't be good, huh. Pull out the power cord and check the fuse in the drawer under the power cord socket. There are two slots in the drawer for the fuses. Be sure you have the replacement fuse in the right slot. Why is this resposnse formating this way? If that is not the probelm, opoen the top and look at the right hand and left hand side boards to seei feither of th4e two fuses for each channel have blown. The big issue will be what is causing it. Let me know how it works out.

Bixby