Air Conditioning/Heater Control

The display on my AC/Heater Control in my '89 is having issues.  It displays correctly some times...but more and more, the numbers now blink or are not displaying at all, etc.  The actual AC/Heat seems to work fine, but the display appears to be on crack! 

Any ideas?  

Loose connection(s)?

Need a new unit? If so, how painful is replacing it?

Thanks!