Topic: PS4 Re-installation Loop/Stuck in Safe Mode

I know this is not a new thing, but it is to me and I was hoping for some help. I was recently given a PS4 and it always starts in safe mode, I get the error "Cannot start the PS4." "Connect DUALSHOCK 4 using the USB Cable, and then press the PS button." I've followed the instructions to where it tells me I need to download the system software onto an external USB/hard drive, when I do that it says its updating the system software and it restarts but when it turns back on its still in safe mode, giving me the same instructions. I've put it into the actual safe mode, and I've initialized it, updated using the internet and external drive, rebuilt database restored default settings, but it still doesn't work. I removed my internal hard drive and blew it out, let it sit and put it back in but I still keep getting the same message. I have been able to get it working and set up a profile and play games on it but when I close it down and restart it, I get back to safe mode? I was wondering if someone could tell me the specific problem or a solution. Thanks