patrickjamesyu

So I have a Line 6 HD100 MK1. I've used it for quite some time. But it's having this issue. When I'm using the clean channel, all things seem alright, but when I use any other setting like twang, crunch, metal, insane etc, after maybe 20-40 seconds, the effects stop working, and it goes straight back to clean (while the LED still shows that the effect is still active) Also the volume drops significantly. The amp is all stock. OEM tubes and all. Any suggestions?