Hi sorry to hear that.
When the unit is on, and set to a low temperature do you ever hear the compressor behind the unit near the floor running?
You will need to remove the lower rear access panel and locate a round black ball part that is the compressor. I need to know if it is humming and warm?
Thank you for your response but I've had to call a local repairer here in England. He tells me that, as you suspected, it's compressor failure and it has to be replaced. However, despite my resorting to a different company, your rating with me is very good since you diagnosed it correctly. Your only mistake was in assuming that I am in any way capable of being 'hands on' - which is why I had to get a local expert in. But thanks, anyway.
Hi Rich, the repair requires soldering and a bunch more. I didn't meant to sound that way:-(
There are many different replacement compressors you can use for that.
If you need me please reply to me anytime:-)
Have a great day!