You can order those chips on alibaba. Perhaps even aliexpress.
Could you replace said chip?
If so, just replace, add thermal paste and heatsink, should be good to go.
Pardon if my suggestion isn't the best, just trying to help. Know a good deal about computer hardware but this isn't my expertise.
What is the name of the chip we need to purchase?
Can you post a link to an example?
I too am having issues with a miner that kills my PSUs after only half an hour.
I can give you a link for a Taobao seller advertising fake antminer chips. No joke - he is openly selling counterfeits that other sellers will in turn resell to us. Seeing that kind of turned me off to looking for a source other than bitmain.