How do you remove the Macintosh SE logic board? It’s fairly simple once you get the hang of it.
First of all, take a look at the logic board at a glance.
20191013/DuckDuckGo remove macintosh se logic board
20191013/https://pc-restorer.com/repairing-a-macintosh-se30-with-no-sound/
20191013/http://pc-restorer.com/wp-content/uploads/2014/02/mac-SE30-board.jpg
At the bottom of the photo is the externally visible connectors. Note that the internal connectors for the internal floppy disk and internal SCSI hard drive plug right into connectors positioned right next to the external ports, and also have similar pin counts. (There are twice as many pins on the internal SCSI connector compared to the external one.) Near the middle bottom of the board is the analog board connector (big white one) and the sound connector to the right side. To the left side of the board, the big long black socket “female” connector is that for the PDS slot, conveniently right next to the iconic MC68000 CPU. Also noteworthy is that the Macintosh SE uses a SIMM slot for a removable ROM module… so that gives you the opportunity to make your own custom ROMs with ease.
Now, to summarize the instructions on the other site. Remove these two internal drive connectors. Remove the analog board connector by depressing and unlatching the locking tab. Now lift up the board gently (i.e. toward the connectors side of the logic board) so that the slots line up with the chassis, and swing it outward (right-side first in the photo). Now you can access the speaker cable and disconnect that. Now you can completely remove the logic board, with PDS card still connected, and you can proceed to investigate what the PDS card has to offer.
20191013/DuckDuckGo macintosh se pds slot connector
20191013/https://lowendmac.com/2000/pds-the-processor-direct-slot/
20191013/https://www.hardwaresecrets.com/inside-the-macintosh-se/6/
Here is some useful information about the Radius Full Page Display (FPD).
20191013/DuckDuckGo macintosh se radius fpd
20191013/http://32by32.com/radius-full-page-display/