If it was bought new, there may be some warranty coverage available, even though it is now overseas. I would contact customer service at Peavey here in the USA, and see if there is any help they can give you. Your US warranty may have no force in AUstralia, but they might be willing to grant warranty coverage as a courtesy. At worst, they say no to you.
I forget the sequence, but there is a re-initialization procedure - hold a couple buttons down while powering up. They can tell you. it might just need that. it may also be in the owners manual - which you can download from the PV web site - under restore factory settings or something similar.
And if there is something actually wrong with it, then I start thinking about cracked or pushed in controls and cracked solder.