i have an output problem, some days when i turn on my pod xt live it starts up fine and works fine like today, about 20 minutes in the guitar output goes completley and all i can hear is dirty high pitched feedback, i can sometimes just about hear the guitar when i play but the feedback is way too powerfull

after the feedback came on, i turned it on and off, and straight away the feedback comes again, some days it works some days it just stops, im sure its a minor output problem but im not sure because im really not used to this product yet, and this feedback problem isnt helping my chances to get used to it..

if someone may know the reason why please help!!