DAC Repair

I have an Arcam rDac as well as a Cambridge DacMagic.  Both experiencing basically the same issue, not powering on.  Mostly concerned with a repair to the Arcam.   Both are small and easy to ship so looking for a reliable tech in the US to send for repair.  I am located in Scottsdale, AZ.

Do they use AC power or a transformer?  If AC often times there is a fuse in the AC socket. 
Are you using the same Power cord for both units?  I recently had a Pre Amp that flickered and apparently died, and when I tried a back up Pre amp it had a loud hum.   Changing the Power Cord fixed both units
I am in New Jersey so you would have to ship them.
Separate power cords/transformers are used
I’ve used Deltronics located in Chicago. They have rebalanced the circuit of my Spectron Digital One class D amp, repaired numerous power conditioners from Furman and Exact Power, and other high-end components.