Sign in with
Sign up | Sign in
Your question

PSU or Mainboard dead

Last response: in Systems
Share
June 6, 2012 6:20:24 PM

Hello everyone!
I got a problem. My computer won't start. When I press the power switch, nothing happens. No fans moving, no noises, nothing. I usually set my pc to standby instead of shutting it down, because I've had this problem before. But back then I just had to press the power switch several times until it finally worked. Now I shut it down for about two days and it doesn't work anymore.
I think either the PSU or the mainboard is the cause. Though I doubt it's the PSU. I unplugged it completely and tried to turn it on with this paperclip trick and it worked flawlessly. I also thought of the power switch being the cause, so I tried to "short circuit" it with a test pen, but that didn't work either.
So what I'm asking is, has anyone experienced this particular problem before? Is my mainboard dead or is it my PSU after all? Thank you in advance!

PS.
I'm sorry if this is the wrong category, I didn't know where to post this. My system is homebuilt, though.

More about : psu mainboard dead

June 6, 2012 6:36:27 PM

Easiest way to find out is to replace the PSU of the broken one with a known working.
If you don't have one to spare you could buy one at best buy or similar store install it and see if it works. If it works then we can rule out the PSU as the cause and the motherboard is the prime suspect.

Worst case scenario is the PSU fried and took the motherboard or other components down with it. I'm not sure the specs of your system but try to get one of equal or greater wattage or if it's a system that was just built make sure you have enough wattage to power everything.
June 6, 2012 6:37:10 PM

How old is the motherboard? Did you check the CMOS battery? I'm not sure if a fully-discharged battery keeps a PC from at least powering on, but it occurred to my old PC that the booting process was interrupted because of a discharged CMOS battery.
Related resources
June 6, 2012 6:50:01 PM

Try re seating the system memory, in some cases this can help. Usually though this only helps when a system wont fully load. For instance if you see the fans come on and the processor fan starts but you see nothing on the screen.

Using a paper clip you can connect or "short out" the green wire with one of the black wires. This will fire up the power supply. If the power supply fires up then you have no issues with it.

What processor and motherboard are you using?

I have a core i7 930 and an AS Rock x58 extreme that does this same type of thing. However the issues lie in the fact of how intel designed this chipset and these boot loops or boot issues are quite common with the hardware I have. I find myself leaving my machine running more often then not. Other wise the machine usually needs to sit about half an hour turned off before it will post.

The CMOS battery will not stop a motherboard from functioning. It might stop it from POSTing but you will see the bios screen and you can boot into the bios menu.

If the power supply isn't powering on the board, and you know the supply works, then mostly likely it's a board issue.

One way to figure out if your motherboard or processor are bad is to remove the system memory. If the processor works correctly then the system will beep continuously indicating that there's a problem with the memory. If you don't hear any "memory beeps" then most likely the CPU is bad or you don't have a speaker on the motherboard. Newer motherboards have little LED displays for bios codes.

Jumper the green and black wires on your power supply at the 24 pin plug. If the power supply kicks on then more then likely you have a bad motherboard.
June 6, 2012 7:05:21 PM

My system specs are the following:
AMD Athlon64 X2 6000+
Foxconn A6VMX
2 GB DDR2-800
Palit GeForce 9800 GT

@brandonkick2005
I already tested my PSU with a paperclip and it turns on.
As far as I know, it doesn't matter if the CPU is bad, because it would turn on even without a CPU (though it won't go past POST), right?

@MKBL
The mainboard is about 2 or 3 years old, I bought all parts around winter 2009.


Also, I already disassembled my computer already and unfortunately, when I tried to take off the CPU, it came off with the heatsink and cooler still attached to it and I can't put it in again, because the heatsink is too big. Furthermore, I don't have any spare thermal paste, so I can't just remove the CPU from the heatsink.
June 6, 2012 7:12:15 PM

marsellus said:
My system specs are the following:
AMD Athlon64 X2 6000+
Foxconn A6VMX
2 GB DDR2-800
Palit GeForce 9800 GT

@brandonkick2005
I already tested my PSU with a paperclip and it turns on.
As far as I know, it doesn't matter if the CPU is bad, because it would turn on even without a CPU (though it won't go past POST), right?

@MKBL
The mainboard is about 2 or 3 years old, I bought all parts around winter 2009.


Also, I already disassembled my computer already and unfortunately, when I tried to take off the CPU, it came off with the heatsink and cooler still attached to it and I can't put it in again, because the heatsink is too big. Furthermore, I don't have any spare thermal paste, so I can't just remove the CPU from the heatsink.


I'm pretty sure you are correct that yes the board will "power up" even if there is no CPU inserted (or the CPU inserted is bad).

I'm not sure what you mean when you say you cant re seat the processor and heat sink because the heat sink is too big. If it was originally on your CPU then it fits. You might have to remove other parts to get it put back on.

As far as the CPU staying attached to the heat sink, that is somewhat common and not really that big a deal. If you can't purchase thermal paste in a local store you can get it online or on ebay. Just clean both the processor and the bottom of the heat sink very well with isopropyl rubbing alcohol.

I'd say your board is dead

June 6, 2012 7:15:18 PM

And on that note be sure you properly apply the paste to the processor. My preferred method is to put about three or four "drops" of paste about the size of a grain of rice or so. You can put one or two on the bottom of the heat sink if you want but I've found this to be unnecessary.

If you put too much of it on then it will actually cause more harm then good in the fact that at best it will cause your CPU to overheat and at worst it will bridge and short out your motherboard. Most thermal paste is electrically conductive!
June 6, 2012 7:23:19 PM

I mean that I literally ripped the CPU out of the socket because I couldn't get the heatsink off and I can't fit it back in because of that little lever on the socket. No pins broke off or got bent or something, though.

About getting the CPU off the heatsink, I don't have isopropyl alcohol, but I read that using a hair dryer could do the trick. But would you also recommend it?
June 6, 2012 7:40:17 PM

So in other words you didn't pull that little lever up until it was perpindicular with the motherboard? This also happens ( not to me though :)  ) and is really no big deal if no pins were bent or broken.

Simply lift the lever up and reseat the processor.

I would not recommend a hair drier. I would recommend you go to the local hardware / dollar store or whatever and buy some isopropyl alcohol (rubbing alcohol) to remove and clean the compound off of the top of the processor and bottom of the heatsink.

Use a little bit on the bottom of a cotton ball or paper towel to do the cleaning. Be careful not to get the paste on your hands and especially careful to keep it off of the motherboard and bottom of the processor while your doing the cleaning.

Put the cap back on the alcohol before you start cleaning. I've seen far too many bottles of alcohol spilled over motherboards.

After everything is cleaned up and the processor is reseated and you have applied new thermal compound simply put the lever back down until it is all the way down and parallel with the motherboard. Then properly attach the heat sink before you start the computer back up. (or try to anyways).
June 6, 2012 7:59:39 PM

The problem is that the heatsink is so big that it's directly above the lever, so I can't set it back in at this time, also because I don't have the means to remove the thermal paste. But thanks anyway for your advice!
!