Gas and Oil Home Heating Furnaces - Wall AC Unit not cooling

I have a similar problem to another member. I have a 5600BTU
Whirlpool AC, which I purchased at Lowes last summer. It never quite cooled my space, (main room is 12x18) and iced up if I put the thermostat past three. I live in Florida, in a mobile home, so it gets quite hot in the summer. I had originally wanted a larger unit, but the salesman at Lowe's said this would be more than sufficient for the space. It worked fine this year, until the outside temperature went past 89, and likewise the humidity went up.
The past two days it iced up each day ( inside coils), and I had to turn it off. Today it simply does not cool at all, and it is not condensing any moisture at all. Before I call in a service person ( the guarantee is past ) is there anything I can do? Or should I just chuck it? I have a much smaller Maytag unit in the bedroom, and it works perfectly. :confused: :confused:

:o :o :o
OOPS
I said my AC was 5600BTU's. I correct myself it's 10,000. However I cannot find the model number, and the instruction book which came with it is a general instruction booklet for all models. I hate that! I no longer have the receipt ( it was a gift ) I realized the output by looking at ads from Lowes, and comparing the prices. The dimensions are 14"x22" and it has manual controls.

When the coil iced up, did the entire coil iced or only a part of it? Was the filter clean?

Now that it is not cooling at all, do you hear the compressor start and run?

It was icing from the bottom up, about halfway. The filter was on the dirty side, but I clean it about every week.

I hear the compressor working but it is not as loud as normal. Normally it feels cold at the bottom of the unit ( inside ) now it is warm. The copper wires ( or extremely thin tubes ) that are connected to the coils are cold to the touch. Just not the coils themselves. I have noticed, that while it seems hot inside, it is still cooler when you come from outside, so it must be working a little. The temp control however has no effect, nor if you turn the fan to high, or turbo cool.:confused: :confused:

The icing on the bottom half of the coil indicates that there is not enough refrigerant in the coil (and probably not enough in the system). The entire coil needs to be cold. This type of problem is covered by the sealed system warranty. Take it to an authorized repair center.