Is the screen going dark as it is supposed to, to conserve power? You can change when the screen goes dark (after how long) under the player’s settings => display => backlight.
Otherwise, you might try a reset. If that doesn’t help, then you could try reapplying the latest firmware and see if that helps–see the firmware upgrade sticky thread at the top of the Clip forum.
Otherwise, I’d continue looking for the receipt and try for an exchange at the store, or with SanDisk via its Customer Service phone line. Note that some stores themselves will be able to look up your receipt.
