after the switch is reassembled and power is restored, connect a terminal to the supervisor engine and monitor the boot process. look for the following messages (or any others), which may indicate a problem with the replaced modules:

    00:00:20: %c4k_supervisor-2-muxbuffernotpresent: mux buffer

    (ws-x4k-mux) 3 is not present

    00:00:20: %c4k_supervisor-2-muxbuffernotpresent: mux buffer

    (ws-x4k-mux) 4 is not present

    00:00:20: %c4k_supervisor-2-muxbuffernotpresent: mux buffer

    (ws-x4k-mux) 7 is not present

    the above messages (either at startup or output from a show logging command) indicate that the mux-buffer is not present in slots 3, 4 and 7. you need to reinsert and reseat the modules in those slots.

    if the switch has already started up, you may also verify the correct function of the new modules with the show logging command.