I suspect most of my suggestions are going to be worthless but, still, here goes:-
I assume your iPad is 3G - as you almost certainly know, WiFi-only iPad's don't have 3G and the GPS functionality is built into the 3G chip in the iPad. WiFi iPads use a different way of determining their position.
Do you have Location Services enabled for the Maps app in 'Settings'? Location services need to be enabled for each app that wants access to the iPad's location.
The GPS chipset requires some time after being initialised to download, from the GPS satellite constellation, a database that contains the orbital parameters of the satellites. Depending upon circumstances, this can take up to 12 minutes to complete. So, if you've performed a hard reset, you might need to wait a little while for the chipset to initialise itself.
Try taking your iPad to a more favourable location - outside would be good if the weather's OK! The GPS signals are very weak in any case and working indoors is a real challenge to the GPS chipset. Also, be aware that, as the GPS satellites are continuously moving (i.e. they're not in a so-called geostationary orbit, where they 'appear' to be stationary above the equator) the geometric configuration of the satellites with respect to the iPad's GPS receiver will vary on a minute-by-minute basis. The GPS chipset needs to be able to receive signals from 4 GPS satellites to be able to compute your latitude, longitude and altitude. At times, due to the signal being blocked by local landmarks or buildings, the receiver may be unable to 'see' sufficient satellites. This most frequently occurs in built-up urban areas where tall buildings can 'block' the satellites' signals.
As I said at the beginning, I suspect these suggestions won't be much help but, just in case....
Tim
Scotland
