I just baught a Meade

I just baught a Meade my sky and I cannot get the darn thing to work. When I select sky map and either enter location and time manually or select GPS fix, neither results in the sky map display. What happens is the screen freezes in either mode and will not accept any input from the keys and I must turn the unit off before it will accept any input. I am about to return the unit and get a refund and am at this point very dissapointed in this product. PLs help.

Thanks, Mark in Slidell, La