Hi to all Apologies if there is an existing thread, but I couldn't find one New to the forums, and more than a little upset at my 6 day new DSL100HR. No issues until yesterday- a home player, no great amp know-how, yet carefully followed all of the dos and donts with things.....Turned on the head, as normal, in stand by mode, waited a few moments before selecting low power on the black rocker switch.....Nothing- zero sounds, checked leads etc....selected 100w on rocker and no problems, business as usual. Tried a few times during the day, and again this morning. All valves appear to be working visually, but I hasten to add that I am more than unfamiliar for the most part with my 1st tube amp head. Of course, it will be under warranty, although I am not one bit happy at such an issue a week into owning it. I haven't done anything that might compromise the unit, living in an apartment and volume kept very low, Hoping I might ask for some far more knowledgeable than I, as to what might be going on here. Of interest (to me, at least!!) is that looking down at the tubes, towards the back a row of taller tubes x4, in front of those, 3 much shorter ones and one looking very unlike the 3, having what looks like a metal collar around it...as best as I can describe it. As said, they all do seem to be working, in so far as glowing goes at least. Living in Cairns, I suspect I may need to send the unit away....wanted to run things past you guys first to hopefully get some indicators of what might be going on. It does seem odd that there should be a significant partial failure of this nature with absolutely minimal and mild use over 4 days. Any ideas and help very gratefully welcomed and, so sorry that my very first post is of a problematic nature. Best Regards, and thanks Lindsay.