New power supply will not power on my computer.?

Question

Switched out the power supply w/ a new one only to find out the old one was still good.(by putting it in another computer) So why wont my computer power on. No leaking from the Capacitors, so what else can it be?

Answer 1

OK, so your power supply was not bad. You see, your Motherboard, RAM and CPU must be working to turn on your computer. Sometimes a lose card is the only problem. With higher summer humidity, some cards quit working.

Try this.

Attempt 1
- remove RAM, then reinsert one at a time and try the system with just ONE. If you have only one, just REINSERT it and try again.

Attempt 2
- remove all PC cards. If your video card is separate, insert just that ONE and try again.

Attempt 3
- remove battery
- look for CMOS Battery jumper, and move to RESET position for a few moments.
- return the CMOS Batter jumper to original position.
- replace battery
Try again

It seems unlikely that the CPU chip blew, but that could be the problem. Be sure to buy an identical replacement.

Good luck and Happy Computing!

Answer 2

Clear CMOS through the jumper or by removing the CMOS battery for 30 seconds or more. PC should be unplugged. Reseat cpu fan connector.

Try the bare minimum set up. NO HDD, CD drive, FDD, just 1 stick RAM and integrated graphics only if possible. This set up should be able to POST and open BIOS menu. Load fail safe defaults in BIOS, save and exit. Reconnect the devices one at a time, powering ON to test the device. The defective device will bring back the problem once reconnected.

If bare minimum set up will not power ON, motherboard could be defective.

Answer 3

too much or not enough power for the motherboard? could be a loose connection, or wires are plugged in wrong.....if the old supply works try putting that one back in and see if it powers up....if not you may have a motherboard problem or a jumper failed or something more severe or less complicated. Best bet is to try using the old power supply and if it won't power up the pc, then start checking all the other spots on the mobo, start by unplugging everything and power up one at a time until failure, then you have it narrowed down.....if it doesn't powerup anything then you have a mobo problem.

Answer 4

Sometimes the simple answers work best. It sounds like you may have a bad power switch. You should be able to unplug the power switch and use a jumper to turn on your mother board. One from a cd drive will do the trick. all you have to do is touch the pins and watch the cpu fan start to turn. Let it boot up and then you can power it down to change the switch.
Remember to just touch the pins and then pull the jumper away. You do not want to leave it on the pins.

Answer 5

Make sure all the connections are good and tight (especially the main power for the mobo). Also, make sure the voltage switch on the back is set to 115V.

Also, there's a slim chance you could have gotten a faulty supply, though that's probably not the case. :)