strange trouble on sun blade 1000

[Riccardo Veraldi]

Hello,
sorry if it is little off topic, because this does not regard FreeBSD.
I am running FreeBSD 9.1 on my sun bladd 1000 but this problem is for 
any OS running on it, not OS dependent.
When I COLD start up it, or when i shutdown and restart it switching off 
the button,
my sun blade 1000 will start turning front leds on but turns off by 
itself after 30 seconds.
nothing is displayed on the console, video is black.
This occour 2, 3, 4, 5 or 6 times it depends it is variable then at the 
end it starts up normally.
Normally after 3 or 4 attempts.
This happens every time I switch it off and try to switch it on again, 
immediately or after 1 hour or after 1 day or 1 month,
when I turn it on again this is the behaviour.
On normal reboot it does not happen.
What could be the reason of this ?
All the rest is working very well on this machine and it can stay up for 
months without problems.

thank you

Rick