Model 1800 radar problems



I have a Furuno model 1800 radar on a sailboat I just bought. I don’t know much about radar, but I followed the operating instructions to the letter, but couldn’t get a picture. The scanner rotates but all I get are the rings on the screen
I spoke to Bethal Marine in Melbourne, Florida, who say it is too old to even inspect. I expect they would love to sell me a new one.
Does anyone please know a good radar man in the Titusville/Melbourne area who could inspect the system which is now off the mast.
Contact ACM Electronics in Jacksonville Beach. 904-992-3761. They have an FCC licensed tech who is based out of central Florida about 30 to 45 minutes away from your location.