Hi guys

I have a fairly brand new Peavey 112+ Tube Combo that is rarely played and now it's giving me issue:

-No sound and feedback, even with the guitar unplugged to rule out possibly dead pick up battery/plug

-If I'm lucky it works perfectly fine for 30 secs then it fades out to nothing

-It's got 5 - 12AX7 preamp tubes (4 are upfront, they are not turning on, while 1 that is next to the 2 power tubes is)

2 - 6L6GC power amp tubes (they are on)

-And never noticed before but after it turns off it makes a ticking noise, kinda like the way a car ticks after you shut it down. Because of the heat perhaps? Just noticed before

any insight would be greatly appreciated........!!