Presario v6000 will not power up

It sounds like you are not getting or hearing any post or beep codes. That would tell us exactly what the problem is.

If you are getting some life out of it then it does narrow things down. On a laptop my first question would be has it been overheating. What you have described is typical of a bad cpu. And those are usually pretty bullet proof except in laptops due to overheating. Once they are damaged all you can do is clean it out and replace the cpu. If ti was shutting down suddenly or seemed warm before it died that was most likely due to dirty vents and cooling system.

If it was your ram you should get nothing at all, it won't even try to start. You can rule out the ram just by swaping it out and trying to start it. If it has two sticks of ram just put one in and try it then take that out put the other in. There is a possability of the ram that is being accesed first being bad. So it starts being used then hits the bad area and poof. Not that common but can happen.

The motherboard is a bit harder to pin down the exact problem as it is so integrated. Without a post code we can't tell what part of it failed only that it has. So to narrow it down to this we have to make sure it isn;t cpu or ram first.

None of these are specific faults on your laptop these are common to all brands.