Ethernet is missing.
I'm not certain, but I suspect 24 port gigabit switches might use a tree hierarchy of multiple switch chips? Eg lots of 5-port or 8-port gigabit ethernet switch chips, then a layer more above those? See if the non-working ports form a distinct pattern of (eg) 4 non-working ports.
EDIT: Also check the switch configuration if it's a managed switch! Those ports might be software disabled or otherwise forced into unusable link modes.
So, I'm not sure what the "switching" chips are that you speak of. Here is a video of a teardown of a similar switch (I have the POE version of this switch, but they are almost identical).
https://youtu.be/bnyCDTA6sME?t=221. I was thinking that it could possibly be the g48209sng chip that is bad. The switch is a managed switch, it was factory reset. Currently, there are 6 dead ports, possibly more that are on their way out. There is a block of 4 ports, and then 2 ports that are not near each other. Seeing as there are 12 chips, it would make sense for blocks of 2 ports to go bad.
The ports with red plugs are dead. They get POE, no data connection.
For what it's worth, when I was testing the ports, some other ports acted odd, only getting 100FDX instead of the full gigabit connection. I went back and tested them again, and now some of those ports that were acting oddly are now working at 1000mbps, so it could be a SOC issue. I'm not sure.