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Dead CPU or dead motherboard?

Last response: in CPUs
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November 15, 2012 12:04:26 PM

Before I really dig into the problem, here are the motherboard and the CPU

Intel i5-3470
Biostar H61MGC Micro ATX

It won't let me post hyperlinks to Newegg, but I am sure you guys will be able to figure things out with that given information.

Before my case arrived, I was running everything out in the open and using a power switch from another case. When my case arrived, I took everything out of the MB (except for the CPU, which I now figure was a mistake), and installed everything into the case. When I tried to power it on, however, the PSU fan would only spin for a few seconds and then stop, and then repeat this endlessly. Same goes for the fans in the case, and the CPU fan would just barely spin.

I thought it was the PSU, so I then bought another one, but still had the same problem. I thought the issue was isolated to the MB until I took out the CPU (but left the CPU fan in to see if it would boot up), and used the switch to power on the MB. The CPU fan still connected spins and the PSU fan spins nonstop, leading me to believe everything is running fine without the CPU in the socket. I have experimented with this, and have kept the CPU in the socket without any pressure on it and turned the power on. Everything runs fine until I try and press down the clamp that holds down the processor, then the machine just goes dead.

I bought the CPU from Microcenter, and honestly I'm kind of concerned about their reliability for replacements. What do you guys think, is this a CPU problem or a MB problem?
a c 104 à CPUs
a b V Motherboard
November 15, 2012 12:06:49 PM

I think there might be a problem with the mobo, if the CPU was dead then the system wouldn't do much.

Try the mobo outside the case.
a b à CPUs
November 15, 2012 12:15:14 PM

When you say no pressure did you have a heatsink on it?
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November 15, 2012 12:19:35 PM

I am uploading a video to YouTube to make it easier for you guys to see. It should be up soon.
a c 104 à CPUs
a b V Motherboard
November 15, 2012 12:27:13 PM

Post a link of the video.
November 15, 2012 12:35:13 PM

Well, YouTube must be busy as it is taking forever to upload my minute-long video. Do you guys have any suggestions to another place I can upload the video to? If worse comes to worse, I'll make an album on imgur and post pictures there. I am horrible at explaining this stuff in words.

I have been testing the MB outside the case for a day now. The only thing on the MB is the i5 and the fan that came with it. I keep the fan on to see if everything is working okay. When the i5 is in the socket, with the latch down to press it firmly against the socket, the PSU fan spins, stops, spins, stops, over and over again. The connected CPU fan barely moves.

When I take out the i5, and just power on the MB, the PSU fan doesn't stop spinning and the connected CPU fan spins like it did before the issues started occurring.

Edit: And no, the heatsink (which is also connected to the CPU fan, its one big piece) is not on the CPU in any of these tests. I am currently uploading a video to vimeo but that too is stuck at 20%...
a b à CPUs
November 15, 2012 1:08:27 PM

Erikman said:
Well, YouTube must be busy as it is taking forever to upload my minute-long video. Do you guys have any suggestions to another place I can upload the video to? If worse comes to worse, I'll make an album on imgur and post pictures there. I am horrible at explaining this stuff in words.

I have been testing the MB outside the case for a day now. The only thing on the MB is the i5 and the fan that came with it. I keep the fan on to see if everything is working okay. When the i5 is in the socket, with the latch down to press it firmly against the socket, the PSU fan spins, stops, spins, stops, over and over again. The connected CPU fan barely moves.

When I take out the i5, and just power on the MB, the PSU fan doesn't stop spinning and the connected CPU fan spins like it did before the issues started occurring.

Edit: And no, the heatsink (which is also connected to the CPU fan, its one big piece) is not on the CPU in any of these tests. I am currently uploading a video to vimeo but that too is stuck at 20%...



If you turned it on without the heatsink then you certainly fried the chip. It needs the heatsink clamped tightly with thermal paste then the temps go over 100 in a second.
November 15, 2012 1:18:09 PM

darth pravus said:
If you turned it on without the heatsink then you certainly fried the chip. It needs the heatsink clamped tightly with thermal paste then the temps go over 100 in a second.


The problem started while the heatsink was on the CPU, though.
November 15, 2012 1:25:16 PM

Damn darth pravus, I now am very glad I just bought a pre-build rig instead of making my own. If I fried and i7 CPU I think I'd have a nervous breakdown/ destruction rampage.
a b à CPUs
November 15, 2012 1:29:18 PM

Erikman said:
The problem started while the heatsink was on the CPU, though.


It may have been something else before. If you don't believe me take your heatsink off and run your pc for a few minutes :ange: 
November 15, 2012 1:37:14 PM

darth pravus said:
It may have been something else before. If you don't believe me take your heatsink off and run your pc for a few minutes :ange: 


The problem is, the PC won't even start with the CPU in the socket and the heatsink over it. So it can't run :( 
November 15, 2012 1:45:15 PM

If you put the CPU in the socket and did not apply the retention latch, you could very well have damaged your CPU, your MB, or both. There are 1155 "pins" on that CPU. Some are power, some are ground, and some are signals. If some of the power or ground pins don't have good contacts, you can conceivably end up with inverted voltages inside the CPU that will burn it out.

Also, if the latch was not down, then it sounds like you did not mount any heat sink. If that is the situation, then the CPU will very quickly heat up, hit the thermal shut-down temperature, and stop. That might exhibit behavior very similar to what you are observing, where the PSU and CPU fans spin up and then stop. The PSU fan is likely driven by a temp controller inside the PSU so it won't need to spin much if it isn't delivering much power. The CPU fan is controlled by parts of the MB and in some (all?) situations by software running on the CPU. Take away the CPU, and no fan control software will be able to run.

Your "base minimum" test config should include the following:

MB
1 RAM stick
CPU
Heatsink with fan
PSU
Diagnostic tool (display, boot code readouts, beep codes, whatever you end up needing).

In addition, it's a good idea to have at least one PATA/SATA/SAS device connected to keep the PSU happy.

We can take a look at your video when you post. It might be a good idea to describe and demonstrate what you did with the retention latch in your video, but WITHOUT turning on any power during the demonstration.
November 15, 2012 2:46:22 PM

take the cpu out and check the pins on your motherboard. is anything bent? i had a similar problem before and realized that it was because some of the pins on my motherboard bent
!