I open up my older Compaq Presario computer to upgrade it with a newer but old video card (3d prophet 4500) that used to be in it. (so I know it should work with it) Anyways, I install the new card, plug it in, hit the power, nothing. Absolute silence. It works perfectly 1 minute and not at all the next. Just to be clear, there is no click, no hum of a fan, zip. I tried using a different power cord in a different outlet and I get nothing, so I know its something inside. All the cables going from the power supply are securely attached to the various bits they go to... Do I just need a new power supply or what?
This is one of Compaq's larger towers so the video card is in an AGP slot... The card I tried to put in has been in the same machine before and it ran very well. How would I know if something was shorted out? Im not all that hardware saavy, what happens when a short occurs? Is there a flash, a pop? This computer just stopped accepting power with no flash or fanfare.
OK I checked the card and it was slightly tilted so that the end of the metal part that holds the monitor connection and stuff was sort of tucked under the same part of the modem card a little. I fixed that, tried turning it on, nothing. I took it out, tried it, took all of them out, tried it, Im not getting anything. I had put the original card back in once the new one wasnt working so it was exactly back to the way it was when it was good.
How can I reset the BIOS without being able to turn it on?
Strange... then there could be something wrong in the card which prevents the PSU from powering on.
You can reset the BIOS by using a jumper on your motherboard in most cases. Otherwise diosconnect the ATX powercable and remove the onboard battery for 15 seconds.
My CPU runs so hot the arctic silver undergoes nuclear fusion .
Uplug the PSU from the wall. Sniff the fan area of the PSU and see if it has a burned smell. It may have cooked without you noticing it and it may not have produced that much smoke. I take it that you don't have any kind of bench equipment to see if the PSU is producing current. The sniff test is barnyard at best, but could give you a clue.
I was just reminiscing about an older Compac I had. It seems to me that to boot the thing, there was a switch on the power supply that has to be on and a front of case push button. It also had a case interlock so it would not power up with the case open. It may sound silly but have you checked all three things?