[Acer Iconia A500] pacificwing:
There are a number of factors which affect the GPS on this unit, as the original poster stated. I've been researching this for sometime, and found a number of things that could lead to a replacement unit working better than a current unit.

I've another thread on this subject, but I'll post the cliff notes here.

The following can affect GPS on your unit:

Obstruction (Roof, Cover)

Weather (Clouds vs Sun)

Internet Access

Nearby magnets

Compass Calibration

Your almanac server (gps.conf)

For starters, download a program called "GPS Test", not to be confused with "GPS Status and Toolbox", which you should also have for different reasons.

Plug your unit in and set it up in a spot where you know you can get a signal on other devices (phone, etc). This does not include your basement, but it also doesn't have to be outside. A woodframe house will not usually obstruct the signal enough to interfere. Use your best judgement.

Start up GPS Test and go into the settings menu. Select the option where the screen stays on all of the time. Check to see if your unit will ever pick up any satellites. If it takes more than 30 minutes and you are sure you should be picking up satellites, this indicates a problem. The first step should be diagnostic.

Leave it run overnight. If you look at it in the morning and find a multitude of satellites then your GPS receiver is working fine. This means your GPS can see the satellites, but the only way it can find them is through sheer dumb luck. It needs to be told where to look, and its having problems getting that information. The problem is likely with your compass or almanac.

If you arrive in the morning to find no satellites at all, then your GPS is likely broken (not unheard of) or you need to try again in a better location.

If you know your GPS transmitter is working, the next step is the check your compass. This is where GPS Status and Tools comes into play. The first screen you see when you open the program will be the compass. Make sure north == north. If it does not, almanac data is useless because the tablet won't know which way to look. GPS Status and Toolbox comes with a compass calibration tool. Use it. If your compass will not stay pointed north, then your compass is broken. If it works, then its time to look at your almanac.

Unless your system is rooted, there is no point in reading further. All the following steps require root access.

There are two files that you need to be concerned with. They are /etc/gps.conf and /etc/gps/gpsconfig.xml

You either need to edit them manually, replace them with pre-configured optimized versions for your region (link below), or use a program (fasterfix) to edit them for you. Results with each approach may vary.

I won't go into this step into detail since its been covered a million times on the forums already. I will provide a link:

http://xdaforums.com/showthread.php?t=1068416

This is the one that helped me the most, but there are others.

Best of luck. And remember: Hardware failure is a real possibility, but so is a crappy environment. Make sure there is no outside interference and you're not trying to get your location from an underground bunker and wondering why it doesn't work. A little common sense goes a long way.

Cheers,

-PW