Slides are nice, but I actually prefer a circular saw for that stuff.For nail guns and compressor I have been loving my Porter Cable pancake rig.

My pet peeve is leaky pneumatic airguns which require a hose, power cord (power) and a noisy, clunky expensive compressor.

We've generally had to pay the maintenance out of pocket over the years - an AC compressor, garage door opener, new dishwasher, paint/carpet etc., but spaced out and we had money in savings for those. 

If it is the compressor, then yes you may have trouble locating that part because of the R-22 phase out. 

Down here I’ve seen inspectors use air compressors to detect leaks and just bring a flashlight for everything else.

Dave at Jacksonville heat and air fixed a compressor on one for me in Jacksonville 351 5450

I made a tester on my own that connects to my air compressor from parts at the hardware store but I believe you may be able to find one online.  

If the A coil is crudded up it will kill the compressor in a year or two and greatly reduce both heating and cooling efficiency.

For example, they left the house vacant for more than two months, and we just discovered that two HVAC compressor units were stolen.

You said you had an electrician there so this has probably been ruled out already but a refrigerator usually requires a dedicated circuit or as the get older and less efficient they will constantly trip the breaker when the compressor kicks on.