Hi,

It looks like the ADAT out port 6 of my ADI-648 is faulty. I first got digital scratches here and there, not knowing where they came from. It then delivered a non-audible low frequency quite at full scale on all 8 channels coming from port 6.

Having some further tests, the device seems to work after powering up and the signal suddenly stops after 10mn. This occurs on ADAT out port 6 only. Even when signal is muted, the front leds still show the incoming signal (port 6). That's what's occurs now, no signal from port 6.

The setup is stable here, since 10 years. ADI slaved to Nanosync HD house wordclock, 48kHz. HDSPe MADI card on PC, slaved to Nanosync external clock too. Everything is in sync and locked, not one single error message on the ADI.

Cables have been swapped and checked, MY16-AT of the DM2k console have been swapped and checked too. I also plugged BNC cables and switched to BNC to check if ever the MADI cables could be the problem. No change at all, MADI cables work properly, which is confirmed by the illuminated ADAT to MADI port 6 led when inputting a signal.

Any idea about what I could check or investigate further?

Thanks!