> removing cores for sanction busting AI cards, reassembling the now worthless PCB with the cooler and scamming some unsuspecting customer that thinks they are getting a deal

I'm either particularly ignorant or this claim has some inconsistencies. My understanding is that you cannot "remove cores" from a GPU. The titular RTX 4090 (Ada Lovelace) comes with 16,384 CUDA Cores. At face value, it sounds like you're saying that Brother Zhang's repair shop uses some nano-technology tools to open up the Ada silicon itself and then somehow disable or destroy or dissect the silicon to reduce the core count. And then they sell these reduced core counts GPUs (???).

That's obviously preposterous, but I'm having trouble steelmanning this to re-construct your actual meaning.