I lost power on the prime 4 and when I plugged it back in the hdd was corrupt. Thank god I had tidal and SoundCloud on it. Anyways long story short I was back up and running a few minutes later. My fix for this is $59.99 and is in the video I’m going to post in here. Hope it helps someone.
Ps I also now carry a backup drive with me at all times.
I seen a video on youtube of someone connecting a small UPS to the Prime4. Same issue as you stated. When you loose power abruptly, the HDD or some tracks could become corrupted.
This is my video 
and after this weekends wedding and the power going out I am so glad I had installed this. Works perfect.
What caused the power to go out ?
That’s awesome. I just purchased my Prime 4. So I have been reviewing as much as possible to identify issues and solve them prior to my unit coming in.
Thanks for sharing your solution and providing a video to assist us. Apparently, I’m a bad reader LOL.
/I’m new to DJing.
First time it was a drunk unplugged my cord to charge his phone. This last time they had too many slow cookers on the same line I was on. They told me I was on my own line. They lied.