BUGERA G5 SOUNDS LIKE IT'S DYING

Good day! So I own a Bugera G5 amp head and absolutely love it. A couple days ago it started losing power or something to that nature. My emulated output does work as well as the send/return. I've changed both tubes now... Not sure what to do at this point... The distortion, loss of power only happens at the amplifier output to the speaker. I've checked my speaker, cables and tired other guitars.  The infinium LED for the tubes sometimes lights up even at a low wattage and even though I've put in new tubes. I give up and need help. Please help!