MXR freaked out, help!

[Kufen]

My MXR m-80 started to distort everything really bad without any forewarning. I've had it in it's box for a couple of weeks, and when I recently pulled it out to play it distorted everything that came in, even with no channel engaged it distorts, and there is almost no difference between the clean and distorted channels. It has had it's fairly new battery in it all the time, but there's no leakage and otherwise tha bettery works fine. Cables are not the issue here. They work excellent without the m-80 to block the signal path.

 

Is there a way to get around this problem without sending it in ? Maybe some DIY-fix?

 

have a nice day.