switch frequently reboot

[welcommen]

my company has a cisco 4009 switch. this switch recently reboot serveral times. because other switch use the same power supply, but these swiths did't reboot. can you told me what was wrong and how to slove this problem

i put sh log result at here

[Bobby Thekkekandam]

Hi,

Could you attach the output of "show crashdump 1"

thanks,

Bobby

[welcommen]

here is the result of "show crashdump 1"

thank you

can you tell me how to read this result, i totally don't understand what it is

[Roberto Salazar]

post show nvramenv as well.

[welcommen]

sh nvramenv 1

PS1="rommon ! >"

DiagBootMode="post"

?="0"

vitConsecTimeouts="2"

vitTimeouts="11"

MemorySize="64"

ResetCause="20"

AutobootStatus="success"

[Roberto Salazar]

Teh crashdumps is invalid and not useful:

Version and date:

Old crashdump format or invalid Version and Date

The show nvramenv show the resetcause=20 which means a power cycle. check power source, power supply. try to plug the switch in secure room where no one can unplug it. and see it get anymore mysterious reboots.

[welcommen]

i will try it.

can you tell me where i find the document that can tell me how to read nvramenv and crashdump