Q: Internet recovery doesn't work

Hello!

My computer (MacBook pro mid-2012) ) has for a while had a defect battery which means I've just had it stationary since one year back. My friend who has the same computer had a defect hard drive cable so I thought that she could just get mine and I'll just have my hard drive externally instead of internally since it's already stationary it doesn't really matter for me. This is where the problems started.

My computer now doesn't boot into anything, it just shows the blinkning map with a question sign. No matter how many times I've tried to boot into it it doesn't work and I do not for the love of my life know what the **** could be wrong? I've tried all the keyboard combinations possible. Anyone here has any ideas in what I should do now? Does the computer require something no matter if it's defect or not to be plugged into the hard drive slot internally?

Thanks.