asian 7750 stops

[manny30]

hello,

currently i have in hand 2 rolex daytonas with 7750 automatic movement. after winding them about a week ago they had about a day of power reserve. now they sometimes last for a 5-6 hours sometimes for 15 minutes. what might be the cause of this? also does it make a difference how the watch is placed down? meaning sideways, with the face down, with the back side down. what might be some things that i can do to resolve this issue before taking it to someone. thanx to all who may reply and hel me with this issue