Nearly got a heart attack today. I've used the search function but I can't seem to find anything from the things I type in there except that I definitely shouldn't do what I did.
So here it goes, I plugged in my 2006 1987X w/LarMar MV after moving it from another room. So everything is set to 10 except the volumes that are set both to 0 and the master volume set at very low bedroom level(about 0.5). I let it warm up, I hit the standby switch, turn the volume1 up a little and there's no sound. What the hell, I reach back to the master volume(installed in one of the output jacks) and I realised I plugged the cab into the loop and not into the speaker jack

So my question - even though all seems fine, could something go wrong from that in the near future? Could the fact that the amp was on for maybe 5 seconds with no load and the master set at about 0.5 on a 10 scale and I strummed a chord or two cause damage if everything plays and looks fine?
Thanks in advance for any replies,
Cebix.