DeLonghi Model PAC-260 Portable A/C .(Discontinued model)
it is in a third floor bedroom.
I can't tell if it's cooling or only fan.
When I go up on a hot day (A/C on high) the room doesn't feel terribly hot but at night I need to blow a portable fan directly on me. (I know this sounds vague)
I hear some switching. I'd guess the compressor is going on and off.
There are 3 lights on the front (A/C, timer and one more) .If I choose Timer, the middle light goes on but the top light NEVER goes on - nor does the bottom light). I assume the top light means: "Cooling is happening"

There is RESET Button in the back. I sometimes press it (while the unit is on) and it seems to begin to cool somewhat better.
I took the back cover off and vacuumed. The filter is clean. The exhaust hose isn't bent.
The best way to say this is this: With a working A/C, I can feel cold air. With this one, I can't tell if I'm feeling fan or A/C.