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No Video, No CPU Fan Spinning

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October 13, 2009 9:45:02 PM

Computer isn't working. Opened it up and noticed that the fan on the CPU heatsink was not spinning. There is also no picture on my monitor.

Tried three graphics card, DVI and VGA, still no luck.

Tried my third party CPU fan (Freezer 7 Pro) and the stock Intel fan that came with my CPU (E6750). On both fans, when I hit the power button, the fan moves just slightly, like a tenth of a turn. Then stops and does nothing. When I hit the power button again to turn it off, the fan spins a couple times and stops.

I don't know what else to try or how else to test my hardware. I think now that it's a CPU and/or motherboard problem - but how do I test that? If I have to buy another CPU/motherboard I'd rather just build a completely new system.


Any tips? Suggestions? Thanks!

More about : video cpu fan spinning

October 13, 2009 10:02:38 PM

if your gpu fan doesn't move, you need a new psu
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a b à CPUs
October 13, 2009 10:47:38 PM

ubernoobie said:
if your gpu fan doesn't move, you need a new psu

Not really, it's the motherboard that tells the PSU to turn on, so if the motherboard has decided not to start (due to fault or other reason), then the graphics card wont get power.

As above follow steps, basically what I do is unplug everything first, and go from there. Could be something as simple as a dodgy SATA cable.
October 13, 2009 10:57:17 PM

It's the CPU fan that doesn't spin. The graphics cards I tried all have fans, and all three worked fine. I also try not plugging in power to one of the graphics card to see if the motherboard would beep an error code - which it did correctly.

I'll try those steps above and report back.
a b à CPUs
October 13, 2009 11:00:35 PM

Have you tried the Clear CMOS jumper?
Might be worth a go.
If you've tried that, and it still wont go with everything unplugged, it's most likely the motherboard (or something shorting on it, give it a good whipe).
October 14, 2009 1:45:50 PM

I tried all the steps listed in the link above with no luck. Just to clarify, this is not a new build - this machine has been running fine for year or so until this recent problem.

I will try taking the battery out of my mobo to reset it. Is it possible that the mobo works for giving power to the graphics card but isn't working for the CPU? Meaning, could just a part of the mobo be broken?

What other things can I do to test the CPU/mobo?


EDIT: Forgot to mention that I took everything apart and gave it a good clean.
a c 77 à CPUs
October 14, 2009 3:00:16 PM

Did you take the system apart and clean it before or after these problems started?
October 14, 2009 3:14:19 PM

I cleaned everything right after the problem happened.

also noticed something else. When I press the power button the CPU fan spins maybe a tenth of a turn and stops. When I shut down the computer the CPU fan spins a couple times and stops.

Besides the CPU fan, all other fans work - graphics card fans, regular pc cooling fans,e tc.
a b à CPUs
October 14, 2009 9:23:18 PM

If you have a spare power supply, I'd try that, but I'd be expecting motherboard failure at this point.

I was changing my NB heatsink last night, accidently got a tiny bit of artic silver on the components next to the NB core (but on the NB unit itself). It caused the '1/10th turn of CPU fan' issue and failed to start. It did however shutdown the rest of the PSU and repeatedly attempt to start time and time again.

If the CPU "crashed" then the CPU fan would be running (I've done this when selecting too high of an overclock, no display, computer just sits there, but CPU fan always runs).
If the CPU "failed" then the system would power down correctly or at least try again.

So for the motherboard to keep power on but not start and not run the CPU fan, I'd expect that to be a failure on the motherboard's part. It might still possibly be power supply, so if you have a spare or can borrow something, try that just in case.

I'm not a computing super god, just posting my thoughts.
October 16, 2009 2:46:13 PM

Tested it with a different CPU and a different power supply. The computer boots, shows a picture and seems to be working. The CPU fan doesn't always spin though which I thought it was supposed to. It doesn't start spining until I get into Windows and start doing something. Then it spins on and off. I guess this is normal?

When I get home from work I'm going to put my CPU and HSF back into the mobo to verify that it is indeed the power supply.
October 16, 2009 5:45:28 PM

Your cpu fan should always spin. Have you tried bypassing the mobo and pluging the fan into the psu directly? Seems liek the lack of cooling fried your other cpu and I think you will be in need of a new mobo.
October 16, 2009 6:15:44 PM

Only thing I can say is that there might be a solution to you problem. I have discovered a little cable you plug into your powersupply like chef7734 said. Your CPU Fan should just plug into that. I recently had the same problem I just removed the mobo battery and rebooted without it...Try it and let me know how things work out for you
October 16, 2009 10:38:29 PM

Ok....

Just put MY CPU, MY GFX card and MY HSF back into my system. Along with all my RAM. Computer boots, and the CPU fan spins while booting. Once I get to Windows it stops spinning. Every second or two it does one spin. Then I launched call of duty world at war. As soon as it started to load the game the CPU fan started spinning like normal. I then left it at the game menu and after it loaded, the fan stopped spinning, and started doing the spin once every second or two. Then I started a single player game. Once it started loading the CPU fan started spinning all the time again. And it spun all the time while I was in the game. Once I quit the game, the fan started to spin once or twice every second again.

I always thought the CPU should be constantly spinning but this changes my opinion. If it was too hot the computer shouldn't boot or should at least crash. It seemed too coincidental that it spun when loading/processing a game and not when it was idle.

I'm going to keep an eye on out with hwmonitor for a couple days but I think getting a new PSU will do the trick.
a b à CPUs
October 18, 2009 7:08:28 PM

It will always spin. Sounds like your motherboards fan control is faulty, as I know you've tried two types of cooler.
Try disabling the fan control in the BIOS. I'd be ordering a new motherboard myself, although it sounds like your CPU might have given up the ghost as well.
October 19, 2009 2:00:47 PM

I don't understand this. I played GTAIV for about two hours last night with no problems. But you're saying something still isn't right? I always thought that if something got too hot the computer would shut down - a heat detecting safety feature.

I'll turn off the fan control (Intel TM2 or something?) and see how it goes.
a c 77 à CPUs
October 19, 2009 2:03:40 PM

What you're describing with the fan sounds normal if the fan control is turned on. My system will completely shut the fan on my Zalman cooler off if the CPU is running below a certain temp. The fan will ramp up when a load is put on the CPU. I wouldn't worry about it at all if your CPU temps look good.
a b à CPUs
October 19, 2009 10:23:51 PM

All sounds good then. 2 hours of GTA:IV is a pretty good test. I'd follow shortstuff's advice and just leave it.

I've never owned a system that shut off the CPU fan completely before (ever).
!