Thank you James, Mag,
Rear power switch was actually off while in storage, and toggled it couple of times since yesterday. Actually, it was even unplugged overnight, in the morning repeated yesterday's result with RCA all the way.
Strange behaviour indded, so setup changed
ext HDD via USB to Oppo 95 via digital coax to SP2 (leftmost COAX in) via RCA to 4BSST playing flac.
SP2 display inactive;
somehow managed to get sound pressing AUX on remote;
from a front panel readout:
Aux: GRN/Dig: GRN/Stereo: GRN (balance knob no effect)
Toggled other source on remote and back to AUX:
Front panel readout became:
Aux: GRN/Dig: GRN/Surround: GRN/Mode: GRN
Toggling Mode on remote audibly went thru various SPs , THX on remote lit GRN, further remote: 2ch bypass GRN lit (no sound); 6ch bypass ORG lit (no sound).
Then following Mag’s advice remote Mode/Save, power down/power up back to:
Aux: GRN/Dig: GRN/Stereo: GRN
And things really went awry – no effect whatsoever from remote, even volume up/down; power down not reacting.
Volume knob down all the way manually/power down back switch manually.
Restart in an hour, front panel readout defaulting at:
Aux: GRN/Dig: GRN/Surround: GRN/Mode: GRN
Talking about manuals since yesterday got both hard copy beside me, Bryston site downloaded onscreen, to little, or no avail.
However, p.8 11: Fuses says ‘Please note that the Analog and Digital power supplies are fused separately. Replace fuse ONLY with an exact equivalent to avoid damage to the SP2.’
Could it be fuses, somehow? How to test if these failed? What are equivalents for SP2-17-230?
Thank you.