computer wont restart on its own

[ecurbnitram]

I've been working on an old Dell machine,  I installed a Maxtor 120 SATA HD. a new CD Rom drive and ethernet card.  I put in a new battery and updated the bio's from Dell.   I loaded Win 2000 Pro and everything is fine when its up and running. 
But this problem started before I did all that.
The problem is it wont restart on its own,  even during the installation, when it called for a "restart"  I had to sit here and manually restart it.  When I hit the power button, it comes on and goes off a couple of times, then finally powers up and boots.  Kinda like jump starting! lol
I've looked around here and on the web, but haven't been able to find any answers.  Anyone else ever had this problem? lol  TIA,   Bruce

[nork]

Sounds to me like either the power supply or the video. Is the video built in or a card?
You mnetioned this is Dell pc. Some Dell pcs have a proprietary power supply that cant be replaced with a generic power supply, other models of Dell use a standard atx, usually version 2.01 or better, something like that.
So you need to find out, from Dell website, if your power supply is generic, standard, off the shelf type or proprietary. If proprietary you may have to get another from them or somewhere, maybe a used pc shop. If its NOT proprietary then you might have another power supply around or could borrow from a buddy. But know for sure or you could really cause worse problems when swapping power supplies in a Dell. I really dont like Dell because of this.

It may not hurt to re-set your bios either. But i would make sure i knew what settings exist in the settings now before you do the re-set and also to set the bootup order correctly as a bios re-set will change that for sure.

[ecurbnitram]

Thanks Nork,  I suspected the power supply,  I noticed also that the jumper that goes on the J7A pins was missing,  not sure when it was removed.  Do you think this would have anything to do with the "restart" problem? This machine poers up fine at times, other times you have to press the power button over and over a few times, then it takes off and boots up.
Also the video is a card.  Do you really think I need to reset the bios after updating them from the Dell web site?
I since formatted the HD and put XP Pro on it, things are running fine except for the "restart" problem.