Remove the controller box. (Controller Box (SP 5300/5310)
)
Disconnect the two connectors, and then release them from the harness guides.
Remove the bracket [A]. (hook×2)
Disconnect the two flat cables.
Remove the IOB [A].
Remove the NVRAM [A] from the old IOB and attach it to the new IOB.
Install a NVRAM [A] so that the indentation [B] on the NVRAM corresponds with the mark on the IOB. Incorrect installation of the NVRAM will damage both the IOB and NVRAM.