Why won’t my console accept an OS?

I bought a PS4 Slim, and have not been able to use it. When I initially plugged it in, it was able to start, but would randomly shut off. I tried restarting, updating, initializing, and no dice. I have gone through 3 different hard drives, all three I’ve confirmed good. The problem now is that no matter how I try to reinstall the firmware, the system alleges that the data is corrupted. I have used 2 different flash drives, hard wire internet download, and have confirmed that the file I downloaded is not corrupted through initializing another system with the same file. I’ve pulled the console apart, and I see no signs of heat damage, no damage to any wiring, or the HDD port. Please help. I’m at my wit’s end, and would really like to see this thing run. Thanks in advance!