Bad Thermostat Box- easy fix?

upstairs thermostat not showing any digital readings ( looks blank) so won't kick AC on. Downstairs one works fine. Replaced batteries and still blank screen. I'm assuming then that the thermostat is bad. Can I replace this easily right now myself? Rather not sweat next few days waiting for an expert but will if it's not a simple DIY. The system may be insured via that PSEG program- not sure if it covers thermostats?

Thermostats can be wired with low voltage or high voltage. Since you mentioned it's digital, it's not original. Can you get a model number from it? My steam heating system is controlled with low voltage, with 3 wires connected to the thermostat. That type is reasonably safe for a do-it-yourselfer. In my family room, I have a digital thermostat that's high voltage. I'm comfortable working on both but you need to be aware of the difference. 

I'f you do replace it, consider a Nest or Honeywell wireless type, easy to control from a smart phone if you're away from home!

Conandrob lives in Westfield, so not safe to assume an old house and not original - (Not that there's anything wrong with that!) 

it's a newer house with all new electric. Husband just started this. He is NOT a DIYer. Now I'm worried...

He tells me he bought a wireless system. Sensei? Should I be more or less concerned?

he will be fine.  

Well, turn all the power off before you attempt it, and follow its instructions carefully. It'z not very complex, I just wanted to alert you of the potential risk. It's more than likely low voltage. you can pretty much determine that by the gauge of the wire inside the box. light gauge wire = low voltage. That wire would be pretty thin, likely about 1/16" inch thick, like old school telephone wiring? 

If it controls both air conditioning and heat, there's likely 5 different colored wires attached to the thermostat harness. Just follow the instructions and match color to color. 

By wireless, does he mean wifi?

I am basking in the delightful ac in my bedroom. He did a great job. No one got electrocuted. Only downside is we need a little paint because it's smaller than the old one (lazy painter, painting around it to begin with!) Thank you!

Nice, enjoy!