I purchased a Mark Bass Big Bang a couple of months ago. Recently, when I turned on the amp after a couple of minutes the sound would begin to crackle and then fade away completely. My experience with bass amps is limited as this is my first big bass amp purchase. A friend let me borrow a fender rumble 500 amp and my speakers sound and work great. I tried cleaning the input jacks as outlined in various posts online but the problem persisted. Any recommendations as to how to tackle this problem?