royalg

im new hear ,so hello to everyone, wondering if you can help?
i have recently come into possesion of a sony fx101 and i have done a couple of upgrades to get dvd drive etc
after this it was all working fine, i put down for a night then turn it on the next day and the system will not boot all the lights come on but only for a spilt second then there is an audible click then it shuts down, holding the power button down causes the system to constantly repeat this, i have stripped the system to see if the upgrades or any hardware is causeing this, with no success, tryed with just ac power.
i really dont uderstand what happened as it was working fine the day before it was left on my table and nothing happened to it
if anyone has any ideas i would be very greatful
thank you in advance