It has been checked. (1st) they thought it was the unit. Ordered a new one, replaced it, still did the same thing. (2) replaced speakers, still goes in and out. (3) amplifier checks out okay. It appears when it is going in and out that it is shorting out because sometimes it doesn't go completely out at first, it cracks as though it is shorting out. Then it goes out. You can cut it off and turn back on in a few minutes and it will play fine, but within a few minutes it starts doing the same thing again. I've been out over $500 so far and still the problem is not fixed. They are stumped. Please help.