Miner keeps going to sleep

I swapped to minerstat from cudominer a few days before the merge and was mining pretty well at 20 ravencoins per day. A few days later and now I can't mine because my PC keeps going into sleep mode when I leave it alone to mine. I'm mining with a personal PC since it's the only thing I've got. Is this related to the difficulty increase or is it a software issue I have to troubleshoot?