Allo Katana no output and Allo digione sig no output

[Sierra audio horn designs]

Hi,

i own an Allo katana using 2 5v linear psu running it and Allo Digione sig using allo battery pack for clean power and 5v linear on the rpi.

Both have been working with no problem for a many months. The suddenly the Allo DG sig failed, and months after the Katana.

both units all show that its playing the Track in volumio as if nothing wrong but theres no out from Katana RCA and also my DG sig spdif and coax output.

ive tried all the usual on the microsd ,update, reflash, back to original flash etc to no avail. Shows its playing track but no output. Also tried many cables, no success. Ive measured supply and its spot on 5vdc. 

ive contacted Allo through email, few times already, no answer, zero.

hoping someones can give pointers on the problem. Maybe a busted output cap? Dont know where to start but looks like its not a software problem as when i used same micro sd card on my running/working dg sig its working ok. 
Thanks

victor