are you sure it's properly filled, or just assuming it to be as it was done 'recently'?

why was the compressor replaced? that's an orifice tube system iirc isn't it? if so, was the orifice tube cleaned when the compressor was replaced?

first thing to check is to manually apply 12v to the compressor clutch briefly (so as not to build up too much pressure) and see if it operates.

not sure on those if the condensor fan should run all the time when a/c on in low speed and then higher speed when triggered by pressure.