As the motor, (compressor) is running, and it is not getting cold, It would suggest, that the refrigerant has gone, usual cause of that is a damaged evaporator, (the plates inside the unit) happens when defrosting, chipping the ice off. If that is the case, it would need the evaporator replaced, not usually possible to repair. Other area of leak, is the condenser, (the big black thing on the back). Same thing, It would need to be replaced if leaking, can be repaired, BUT. Costly to repair. Due to to cost of the unit, (expensive, I have one) Probably less than a new one. But as your is over 8 yrs. Well. It would probably be a bit cheaper to repair, depending on who you get, Depend on the problem. Could be no gas, could be something else, But as the Motor is running.
SD, July 2011