Fully tested original Apple logic board for a Macintosh SE fitted with an 800K floppy disk drive. For an SE that was originally fitted with a 1.4MB floppy drive, you should use logic board part number 661-0536.
Logic boards from machines that were originally fitted with 1.4MB floppy disk drives can be easily identified by the fact that their backup battery is removable and in a plastic holder. The battery on versions originally fitted with 800K floppy drives are soldered onto the logic board.
NOTE: To determine if a board has been upgraded. check the Apple part numbers on the ROM and floppy controller chips:

ORIGINAL SE
342-0352-A - HI ROM
342-0353-A - LO ROM
344-0043-A - IWM

UPGRADED TO 1.4MB FD
342-0701 - HI ROM
342-0702 - LO ROM
344-0062-01 - SWM

This logic board has NOT had these chips replaced so if you want to use a 1.4MB floppy drive (superdrive), you should either use the version on our store that has bene upgraded or if you are replacing an upgraded logic board, transfer the required chips from your old logic board.