need help in e -250

hii all

i have e -250 with configuration 4002 processor(sparc) with 2 gb ram\364 hdd\

problem:- the machine gets poweroff automatically where should i see the error message whats the problem happening i have update all patches i have changed the power supply and distbution box then also the problem persist. once it gets power off,and if i tried switching on it wont come so easily .it checks the ram and detects the hard disk drive it gets powered off automatically . so can any one help me out on this

i updated all patches and tried this
/etc/init.d/power stop

then remove the following packages:

system SUNWpmowm Power Management OW Utilities Man Pages
system SUNWpmowr Power Management OW Utilities, (Root)
system SUNWpmowu Power Management OW Utilities, (Usr)
system SUNWpmr Power Management config file and rc script
system SUNWpmu Power Management binaries
system SUNWpmux Power Management binaries (64-bit)

again the same problem coming back, i have removed the power mangement software the also the problem come even no logs comes in var it switches off of it own now what should i do can any one help me out.can it be switch problem ( on & off switch)
pls help me out in this problem

regds

You might try:
/usr/platform/`uname -i`/sbin/prtdiag -v

It it won't restart easily I would certainly suspect a hardware problem. See this for some info on reading the lights.