Need Help! Cisco 3850 48PoE switch

Hi All,

Im a Help Desk Manager and we recently had to let go our network engineer and i kid you not, the next day the internet goes down. I Have just very very basic knowledge of all things networking but managed to get a few people hardwired connections.

I know the problem is the Cisco 3850 thats the problem because when i walked in, all the AP's were off. I look in the MDF and theres just a blinking green light over "SYST" which i think its failing POST?

We have a Cisco 3850 switch in both our MDF (1st Floor) and IDF (2nd Floor). The MDF 3850's port 48 was set up to be the port that accepts the incoming internet via ethernet. The IDF 3850 was set up to accept internet via fiber via fiber cards in the front.

1. Would it be easier to just swap out the 3850's and change the IDF's port 48 to be the internet input? If so, how do i do this??!! Really, I need to learn this

2. would it be easier to fix the blinking green light?