Im troubleshooting the same thing here and on #12… How long is a few minutes? Its been 20 min so far and its still testing. My E and T are still 0. Is it safe to tuen it off? 

Please do the following:

1) Set DIG-IN to XLR or RCA according to which you use.

2) Set SR-CNV to OFF

3) Set CLOCK to INT 48.

4) Plug a cable from the digital input to the digital output specified in (1).

5) if EXT is off, go to (7)

6)  If EXT is always flashing, your unit or cable are faulty. Try a different cable and to to (4).

7) Disconnect the digital cable. If EXT does not flash, your unit is faulty.

8) Reconnect the digital cable, and restart the unit with ‘5’ key held down.

9) Release the key immediately you see “001 Test All”

10) Turn the knob until you see either “510 AES Digital” or “512 S/PDIF Coaxial” as appropriate.

11) Press TAP. The “P=” number should increment every few seconds.

12) Let it run for a few minutes.

13) If either the “E=” or “T=” number are not zero (0), your unit or cable are faulty.

14) If your unit is not faulty, there is some problem with your setup, and you should seek local technical help.