I suppose if they are series(as logic ICs should NEVER be) and they are shorting to ground you're going to get a lot of burnt connectors and I am seeing a lot of those here and on eBay. But slowly going out one by one that has to be completely unrelated to power delivery, unless it's the power supply is sending noisy power then there is no causal relationship between the first going out and any others, they are just all the symptom of the one continuous PWS malfunction. One other option , and that one is causal , when the first chip goes out it doesn't truly die it just goes insane, sending spurious signals throughout the whole power bus killing the others one by one (haha, I should call this the zombie theory ). Since you think I should do some more research maybe you could point me to the data sheets or maybe the schematics, lol thats funny.
You watch ipadrehab and you want schematics. They are not public - not like Mac not public, like "don't exist outside of Bitmain for >S4" not public. The chain is very real and very much how it's implemented. I am unsure of how much University education is worth given the above statements. Research and learn first. Buy your own kit and repair it before offering a "no-win no fee" service which will end in tears.
I would seriously suggest not sending boards to people who don't have a proven track record with antminers or at the very least modern ASIC miners.