need estimates for lawn treatment in pasadena md. grass is turning brown

hello,

just moved into a property with a HVAC about 10 years old. it does not blow cold air when turned on. the unit outside runs, the fan turns. a while back there was a lot of rain and wind and a large piece of fence fell on the unit that seats outside. i suspect it may have caused some damage. 

i had 2 companies look at it. they are saying the frion (coolant is low). they said they might be a leak somewhere and are suggesting a replacement the entire system. 

i would like another opinion for repair and estimatr. 

thank you,

Ben