I guess this comes down to honesty. If you ran this sytem yourself before selling it and knew for a fact it ran as it should have. Then your in the clear. Maybe it was user related or it was just it's time to die. Nothing last forever. But if there's a question about it functioning and running and maybe you got it in trade and never ran it, well then... I could see a set up run with no load for a second, but keep cutting once installed. If you sent it not knowing than maybe a refund is in order, if you know it was ready to rock then your good.