Looking for info on these extra PCBs/Chips in S9 boards

Hey everyone I just grabbed an S9 for a steal and opened it up for a little cleaning. I noticed these extra PCB boards inside. I've never seen anything like this on other S9 boards before. Does anyone have any idea what they are and what purpose they serve? Appreciate any thoughts! https://imgur.com/F3Pr7PF https://imgur.com/ETk5XcR

I don't see any difference between the old s9 hashboard compared to your hashboard. You might be just purchased a used miner with a recon(repaired) hashboard. Those parts are the most common issue like a shorted so possible that part in your hashboard disconnects all connections and replaces a new small board to bypass power or to fix the shorted part.

I saw this module for the first time, but it doesn't look much different from the original S9 hash board, except that the positions of several triodes have changed. It can be seen that this is a repaired hash board, because this area is the power supply route of the S9 hash board. Once this area fails, the hash board will not work.