Power turning on problem

[Phase-Six]

Okay So I hook up all the parts to my older pc that I had used a year ago and I found out that with every power supply I use as soon as I plug it in it starts automaticly. no buttons pressed. Even if I dont plug in the case to mobo wires then it will still do it. Any possible answers to why its doing this? Motherboard is an ancient pentium 3 by compaq lol!

 

[carnageX]

I've noticed this on several older PC's I've worked on. Unless it has a switch to manually keep it off... it's going to do this.

 

[Phase-Six]

I've noticed this on several older PC's I've worked on. Unless it has a switch to manually keep it off... it's going to do this.

Hmm any chance of ressetting the bios gonna help?

 

[carnageX]

Are there any options in the BIOS for something like "Auto-On" or anything like that?

 

[Phase-Six]

Are there any options in the BIOS for something like "Auto-On" or anything like that?

I just checked through it and it doesnt have anything like that. Any ideas of what else it could be called? I also played around with the settings but no luck. idk what it is .