Sun T2000 activity LED in slow blink even though Domain is up

Hello All
I have a SunFire T2000 running f/w 6.3.2
The activity led is in slow blink mode.
this typically indicates that the domain is down, however it is up and running.
I had this issue before and resetting the sc fixes the issue, but now it has come back. showfaults from the sc indicatess no problems. showlogs has a huge amount of "sc login failure for user" errors, but I don't see how that could be responsible.
showlogs also indicates "Host System Has Reset" and "Host System has shut down", yet the domain is still up. showplatform indicates that the OS is "running"

anyone have any experiences like this?

If you are talking Enterprise T2000 then 6.3.2 is quite old. First thing to do is to update the firmware.

I've had many an issue with old T2000 firmware, like a complete crash whilst updating Solaris revs. That turned out to be firmware too old.