Which is more likely to be dead?

[Tygur]

This explanation is going to involve two different computers. Computer A is the one that I want fixed. Computer B doesn't really matter at all.

I'm trying to figure out what's wrong with this computer (Computer A). When you try to turn it on, the power light comes on and the fans start spinning, but that's about it. No beeps at all, and the monitor doesn't get a signal. The hard drive light doesn't blink or come on either. I interpret this as meaning that either the Motherboard or the CPU has a problem, and the power supply could also be an issue, but it's less likely.

I have another computer (Computer B) that isn't being used, but it's showing the same exact symptoms, anyway. It was working fine until it took a ride in a car from one place to another. Then it started having problems, and nobody wanted to deal with it.

In spite of its problems, I decided to try swapping hardware, anyway. After each hardware swap, Computer A still exhibited the same exact symptoms. I suppose this means that either both computers have the same problem, or the motherboard in Computer A is the problem.

Things I tried putting into Computer A from Computer B:
CPU
CPU and Power Supply
Power Supply
Video Card (I was desprate)

It looks like it's time to get some new hardware for Computer A, but I don't know what I should be getting. My question is what is most likely to be wrong with Computer A. I figure I'll just try that first.

[Droppyale]

did you reset the CMOS?

[Tygur]

No, I didn't, so I went ahead and took care of that just now. After clearing the CMOS, I tried the CPU from Computer B with both power supplies. Nothing changed.

[astronaut1]

Just a question, do you have another computer that is similar to the two that doesn't work? If so try to put some of the suspect components into a similar computer that works.

Also you might check to see if the fuses in either of the PS are blown. Double check the PS connections to the mobo.

If they aren't get a multimeter and check the voltages.

Good luck

[DoctorReno]

How about memory? Have you made sure it is seated correctly? If you have more than 1 stick try removing the other(s) and starting the machine.
Does the light on the floppy drive do anything ie. flicker, come on and stay on etc?
Although you say the HD light does not come on, can you hear or feel if the HD is spinning up? First touch your chassis to make sure you ae discharged and then put a finger on the HD lightly. You should be able to feel a slight vibration if it is running.
Since you have moved the PS's around you are certain that you have it plugged into the MoBo nice and snug, correct?
The fans you are talking about.... this would be the one in the PS and the one on the CPU also? Where does the fan for the CPU get its power... do the wires come from the MoBo or does it plug into one of the connectors from the PS?
Have you tried disconnecting everything except the absolute essentials to see if it will start then.... disconnect all HD's CD drives, pull all modem, sound and network cards etc. All you should need is memory and a video card.

I'm just trying to think of troubleshooting ideas here that are the most basic and eliminate them as we work thru checking things logically to find the problem.

[MDS]

first off what are the two motherboards? and what processors do they have? What type of ram are you using?

[Tygur]

Originally posted by astronaut1
Just a question, do you have another computer that is similar to the two that doesn't work? If so try to put some of the suspect components into a similar computer that works.

I might try that tonight. The problem is that all the computers that work get used.


DoctorReno:
The only thing I did with the memory is take it out and put it back in. There is only one memory stick in this computer. The HD does spin up, and the HD light does light up for an instant right when I turn the PC on. Since it lights up like that whether or not the HD is actually connected to the Motherboard, I think this only means that the light actually works. Yeah, I did plug the power supplies into the motherboard nice and tight until they clicked in. The fan for the CPU is plugged into the motherboard. It and the one in the power supply are the fans I was talking about. While I did try disconnecting the hard drives, I never took out the PCI cards.


MDS:
The motherboard in Computer A is labeled as a WinFast K7N420DA, and it has a 1.2Ghz Duron processor. It has one 256MB stick of Crucial PC2100 memory. The processor from Computer B is a 900 Mhz Athlon. The motherboard in Computer B is a BIOSTAR M7VKQ.


I guess I'm going to start swapping parts with a known-working computer tonight and see what happens.

[imac9556]

Hey, srry if this seems too obious, but did you try connecting the PC to a different power plug or different surge protector? just a suggestion, thanks

[scotlandtb]

ok may sound crazy but try taking ALL the ram out and turning it on do you get POST beeps, possibly try it with the video card also, both of these you should get post beeps from the mobo, which is a good sign that mobo is still thinking fer itself. Also try powering it up after this if you did get beeps - put the components back in. I've had that work quite a few times (the last one only being last night with my new Vid card.)

[Tygur]

I took the CPU out of Computer A and put it in another computer that is known to be working, and the computer acted just as unresponsive as the first two. After putting its normal processor back in, it was working fine again. Yes, I did clear the CMOS this time. This computer has a Gigabyte GA-7ZX mobo, and according to the Gigabyte website, it is apparently supposed to be able to take the 1.2 Ghz Duron.

At this point, it is looking like the problem lies in the processor, but I don't understand how it got messed up in the first place. I'm starting to become suspicious of the power supply, because it is a cheap one.