Will Unplugging freeser cause it to stop working

I have a freezer and it ran fine. Had been in the same spot for 15 years. It was unplugged by my renters and when I plugged it back in it wouldnt get cold again. On a freezer that old is it bad to unplug them. I have heard that sometimes on old compressors, that they run for-ever but if you unplug them for awhile. This was 15 days, that they just dont start again. Is this true? Is it worth having it looked at to be repaired?

Thanks
Grant

For your problem, I suspect your cold control stuck open. Try spraying it with a non-residue contact cleaner and turn the knob while spraying.