Jump start works, but nothing happens when PS plugged in mobo - dead PS or dead mobo?

[Kadence]

I was doing a new build, but after I finished and turned the power on, the fans turned on but there was no signal to the monitor and a red light on the back of my GPU was on. I turned it on again after rechecking to make sure all connections were tight, but there was no change. I tried unplugging and removing the GPU and using the HDMI output on the mobo only, but there was still no signal to the monitor. Then I tried again a few minutes later and nothing would happen at all, no fans, no noise - not even the fan for the power supply itself would turn on.

After googling and reading that one of the reasons for a red light on the GPU is that there is not enough power, I figured perhaps my PS was fried. I had a Rosewill 450W supply and an HD4850. I had read a 450W supply was necessary for the card, but I didn't know about the certified PS list, and apparently the Rosewill is not a good PS (the Newegg reviews were good so I didn't realize this).

I tried jump starting the PS - I used a staple (didn't have a paper clip), and inserted one end into the green wire hole and another into a black wire hole. After a couple seconds the power supply turned on - and the fans that were connected to the PS by molex also turned on. However, when I plug the PS back into the mobo and turn the power on, once again nothing happens - a green light on the mobo turns on, but the PS fan doesn't, nor does anything else.

So, does this mean my PS is broken? Or is my motherboard dead? Or perhaps even something happened to the CPU? Is there a way to tell?

Here are the specs for my build BTW:
*2x1GB DDR2 800 RAM
*Intel BOXDG43GT motherboard
*Asus 24x DVD burner
*Seagate 1.5TB SATA HDD
*E7200 CPU
*HD4850

 

[PreferLinux]

Probably the PSU.

 

[Kadence]

I just bought a new supply, the Corsair GS700. This had the same problems - a single green light on the motherboard turns on, but nothing else, not even the power supply's fan. So I guess the jump start test was right and the other supply still probably works.

The means it must be either the motherboard or CPU right? Is there a way to tell if it's one or the other - would there be any difference in the symptoms? It might be the CPU because it's an older one I haven't used for a while. If the motherboard were OK then I would assume the power supply fans would be turning on right? Or would a broken CPU also cause the circuit to fail?

 

[john3850]

I would clear the cmos {reset bios}
Your memory could be bad or needs more then 1.8 volts to boot
Be sure you dont have any tim on the bottom of cpu.
Next try only 1 stick of memory at a time in slot one.
Bad memory is very common.
The mb or mb bios could be bad.
A bad cpu would be the last on the list.

 

[Kadence]

How would I reset the BIOS without being able to get anything to turn on?

I don't think it's the memory, I removed both modules but that didn't help. It should at least boot up and give me an error message in that case I believe.

 

[BoomerD]

How would I reset the BIOS without being able to get anything to turn on?

I don't think it's the memory, I removed both modules but that didn't help. It should at least boot up and give me an error message in that case I believe.

You "reset" the BIOS by clearing CMOS.

Unplug the PC from the wall, remove the battery from the board, and also by changing the jumper on the pins. BE SURE to put the jumper back to its original position before powering the computer up!
Here's the manual for that board...you can find the jumper on page 11:
http://downloadmirror.intel.com/17807/eng/DG43GT_ProductGuide01_English.pdf
It's "item X" on the picture.

 

[Kadence]

Thank for the info. I already packed the mobo away though to exchange it, hopefully the new one I get works otherwise it must be the CPU.

 

[Yellowbeard]

Could it be a bad power switch on your case? You can always switch the power and reset buttons or manually short the power on pins on the MOBO to test. I guess you'll probably find out when you put the new MOBO in.