Ps4 Slim and Ps4 repair questions

I have a Ps4 and a Ps4 Slim. Both of them have stopped working. I was playing the Ps4 when it happened, heard and saw a loud snap, then it died. I found my Slim unresponsive when I arrived home one afternoon.

I am purchasing a power supply for the Ps4 and replacing it myself (as repairs cost twice as much). Though, I'm hoping its just the power supply. The repairs would cover everything, but if I just put a new power supply in and that's not the only issue, I just wasted my money.

Also I'm wondering, instead of having to re-download things and such, could I use the Ps4 Slim Hard Drive in the normal Ps4? If so, could i just put it in there no strings attached?

Another thing, if anyone can help me find a Ps4 Slim Power supply I would be so grateful. It was hard enough finding the CUS-1215A power supply. It seems both models I have are the most difficult to find parts for, how unfortunate for me...