Dead cpu fan (i7-3770 Ivy Bridge)

The_Outlander

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Jan 12, 2013
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So yesterday I finally completed my nightmare of a first build (and marveled over how quietly it ran). I was testing various aspects of my new computer and I was finding a way to monitor cpu temperature and fan speed. I was surprised to discover that the cpu fan wasn't spinning at all. Thankfully my four case fans were running so I think the cpu is ok (I am typing this from the new computer, all the cores are at about 52°C, but I doubt really dare to do anything other than web browsing).

I am running

cpu: Intel Core i7-3770 Ivy Bridge (with the stock cooler)
motherboard: GIGABYTE GA-Z77X-D3H

so basically I have questions.

1. I was under the impression that a computer could not start without a functioning cpu fan (one of the reasons I took for granted the fact that it might not be running in the first place) is that not true?

2. I'm pretty sure the fan is dead, but are there any methods I should try and test/fix it anyway? I could try plugging the cpu fan into the system fan 1 port, but I don't know if that would be a good idea.

3. Since RMA'ing is no longer an option (Newegg screwed me pretty hard and I'm not happy about it) and the cpu itself seems to work fine I was thinking about just buying an aftermarket cooler. Is this (http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1927342&CatId=493) a good choice?

4. The cooler in the link apparently comes with thermal paste, but there is thermal paste already on the cpu. Should I apply more?

I must say I am not happy about this situation. I was basically supposed to be having a "honeymoon" with my nice new computer,but now if I want to do anything more intense than watching a video on youtube I have to take out the videocard and put it back in my old crappy computer (my decision delay upgrading my gpu was also influenced by incompetent Newegg customer service reps). Any help would be very much appreciated.
 
Hi

Check BIOS options for CPU FAN

whether PC will not start without cpu fan is often a BIOS option
there is also maximum CPU temperature before shutdown options
also options for FAN speed :- should it be controlled by BIOS or Intel driver or run at full speed all the time

CPU should be slowed down to reduce power & temperature before damage occurs (either by BIOS or Windows driver)

Check wires from CPU fan to motherboard are not fouling fan blades (can easily happen on Intel CPU Heat sink fan)

You could try plugging fan in different fan socket to see if it runs there.

If you remove heat sink you must clean off thermal paste from CPU and old heat sink
(methylated spirit or pure alcohol will do)
If there is thermal paste on the new heat sink that will do, but check for plastic film covering thermal paste which should be removed before fitting
(Stock Intel heat sink does not have plastic film)

Too much thermal paste can cause overheating as can none

regards
Mike Barnes

 

lysinger

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Nov 26, 2010
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Your first build is not supposed to go well. It's supposed to be full of problems and frustrations, or just generally suck. Mine was a 286 12mhz mb swap in an IBM PC XT. It did not go well. My folks were not happy. I was 12. It made me the IT tech I am today 25 years later. Luckily there were some folks that helped me out in my monent of panic. Luckily you have the Internet because we had to call people on land line phones and pray that they had answers. But I digress...

Mbarnes86 has given you a lot of good information.

To reiterate, CPUs and MBs have overheat protection nowadays.

Many MBs will power up without the CPU fan working. Dells are famous for it and then they chirp that there is a fan failure and then shut down a minute later.

I would like to add that the Intel cpu cooler setup with the plastic push pins is lousy on a good day. Replace it it you have the money (thermaltake sells $10 cpu coolers and $25 low profile CPU coolers).

The reason to go with aftermarket coolers is the backing plate. You will have to yank your motherboard and put a plate on the bottom of it, but the work is worth the effort.

If the stock cooler isn't pushed down and locked on all 4 points correctly, then you are going to trip the thermal sensor. Due to the different heights of the CPU mounting bracket, your Intel cooler may or may not fit perfectly. It causes the Motherboard to bend, and that is not good for long term use. Backing plates eliminate this problem.

Also take a moment to check the MB manual to make sure you have the CPU fan plug on the CPU fan power plug on the MB and not the chassis plug. I've made that mistake a few times.

You can run the CPU for a little while without the heatsink paste while troubleshooting the fan issue. Don't do anything CPU intensive at this time, get the fan working or replaced. Then put paste back on the cpu.

Plugging the cpu fan into the system fan is okay, I ran a server this way by accident for 3 years. As long as there is power to the fan to keep the CPU cool, it doesn't really matter where it comes from. The bios still throws an error though.

Hang in there and enjoy this adventure. The next build will be a whole lot easier! (not easy, easier)
 

The_Outlander

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Jan 12, 2013
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hmmm... So I just tested the cpu fan plugged into the system fan 3 spot and now it works, which honestly kind of surprised me. I did also clean up the wires around the fan a little bit, but I'm pretty sure it wouldn't have made a difference. The only other difference is that my video card is not currently installed, but that shouldn't matter.

I am disappointed in the manufacturer of this board. Still though, I think I might have to settle right now and use as is (maybe when I'm feeling braver I'll consider a better heatsink). I seem to be getting pretty good temps right now (idling at 29°C right now) and there are so many things I want to use this computer for this week. I will definitely have to test to make sure I can get good temps under load though.

I appreciate the good advice and encouragement you guys have given me. I still have a couple questions though.

1. Lysinger, are you absolutely sure I can run the cpu fan of the system fan slot without any ill effects?

2. I think I can control the fan manually through a utility provided by the board's manufacturer, but I may also be able to do it through bios. What is the best option?

3. The fan is running at 1493 rpm right now, so what is a good default speed to have?
 

lysinger

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In regards to the heat sink, if it were not clamped down correctly, you'd have overheat shut down issues right away. I'd run with it as is for now and feel the IVB love.

There are no absolutes, but I can tell you that the fan is a motor that draws power and the chassis fan power socket will supply enough for the cpu fan.

Always control the fan in the BIOS if you have a choice. Software control is great until you swap a hard drive and forget to reinstall the fan utility.

~1500 RPM is the default for the fan at slow speed. When you game on it, it should jump to ~3500. check the bios, you should be able to force it to high speed just to verify that it can do it. Or use speedfan to verify. Then you will know it will kick into high gear when you need it to.