Is there a way to lookup old flight status info from more than one day ago?

My father was on UA835 ORD-PVG 6/1 and UA836 PVG-ORD 6/9. He said there was no power on that plane (in Y) eventhough when he called to make his reservation he was told there would be. I looked up the status of today's flight and a few others and they all have power and thought it was strange since they often use the same plane and have power on planes for flights that long. I'm wondering if they switched equipment recently.