Empirically, I have brought modded Macs to Apple Stores and they have fixed unrelated issues without saying a word. IANAL but there are consumer protection righ

Empirically, I have brought modded Macs to Apple Stores and they have fixed unrelated issues without saying a word. IANAL but there are consumer protection rights keeping your warranty rights depending on where you live if you don't actually cause a damage while you're adding a HDD (FFS, it does not even need soldering or anything; more like playing with Legos: https://www.ifixit.com/Guide/iMac+Intel+27-Inch+Retina+5K+Display+Hard+Drive+Replacement/30522 https://www.ifixit.com/Guide/iMac+Intel+27-Inch+Retina+5K+Di...). BTW, iMac 5Ks have been out for a few years now. Many of them are probably out of limited warranty anyway. $5k is quite a bit of stretch on the price approximation for an average iMac out there too. In my experience, going to an Apple Store as opposed to an authorized repair shop is the way to go (I have had bad experience with the latter). Charming the "genius" on the other side of the bar is not a bad idea either. :)