Tools, Sharpening and Power Machinery - Air compressor problem

I have a Cra**sman air compressor small 3 gallon one (I am guessing that it is oiless) but I have had it for a short time not even a year. I did build a pretty big deck with it but only used it on that for a couple of days sperratically. I used it 2 weeks ago to nail up down a few boards and put it up in the shop. Got it out last week and now it won't go past 20lbs on the selector guage no matter what I do. The motor runs fine just won't pump up. Anybody know how to fix it? It has to be something simple! All help greatly appreciated!:wall:

Does the pump shut off but the pressure will not go above 20 psi?
If so it is possible that the pressure regulator is not set at a high enough pressure.

If it continues running but does not build pressure then you likely have a problem with the pump.
There is a possibility that even though you did not use it much these units have a very low duty cycle.
If you do not follow the instructions carefully it is possible to burn it out in a day.

Also, not knowing what type of compressor it is doesn't help us help you.
Besides all this, the thing will still be under warranty.......... return it.

Here (http://forum.doityourself.com/tools-sharpening-power-machinery/131654-air-compressor-information.html) is some compressor info.