Apple says T2 chip can limit third-party repairs for recent Macs
 

Yes, the reports were true -- Apple's T2 chip can potentially restrict third-party Mac repairs. The company confirmed to The Verge that the co-processor can limit third-party repairs for certain components on recent systems, likely including the iMac...

https://www.engadget.com/2018/11/12/...r-recent-macs/