Replacing MacBook Pro (13-inch, Mid 2012) logic board As in the title, I have quite an old MacBook Pro. I bought it in 2013, and recently on some apps or webpages, at random times, my screen is glitching on the top side. I tried checking to see whether it's a screen issue or not, but when I tried to connect it to an external display, the glitch still appeared.

So I made an assumption its a graphics issue meaning a logic board issue.

My questions are:


What will happen when I change to a new logic board? I mean I am a custom PC user before, but I never tried to change a motherboard / logicboard on a laptop before. Will it have an issue with the software? 
Can I replace my logic board with higher version of my current logic board?


ie.


My processor right now:  2.5 GHz Intel Core i5
I want to get: 3.1GHz dual-core Intel Core i7 processor (I'm not sure this type is compatible with mine since it's the latest core for "old" MacBook Pro in the site, but I hope you get what I mean)
The only logic boards guaranteed as compatible with the Mid 2012 13" Unibody MacBook Pros are either the 2.5Ghz (core i5) as you have now or the 2.9Ghz (core i7) unit also used for this model.

The cost of replacing these depends on where you're based, where you purchase from, and whether you buy a new, used or refurbished logic board.

Before considering such a replacement you should also consider whether you feel comfortable doing this yourself or not? You can review the MacBook Pro 13" Unibody Mid 2012 Logic Board Replacement page which details the tools required and steps involved. If you feel comfortable doing this, then you can decide whether or not purchasing a replacement logic board is an economical exercise or not.

Without knowing your location, I can't really recommend a retailer to purchase one from. However, most users who undertake this themselves will purchase replacement parts online from places such as eBay and Amazon, or from some specialised online retailers such as iFixit or We Love Macs.