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Computer turns off then on, No screen after upgrade to new cpu cooler

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September 30, 2012 10:51:32 PM

Hey guys,
Long title, huh? :D 

So I got this new CPU Cooler (Noctua C14) today for my i5 2500K after Ryan suggested it in overclocking forum to me. I did a little overclocking before installing the new cooler to compare the stock and C14 temps. (OC was stable, did it with Ai Suite)
I removed every component besides cpu and stock hsf and took out the motherboard to install the NH-C14 (after reading manual and watching a video on youtube.)
I was very careful about static and I used a very small amount of TIM. Put everything back, connected power cables (both)...
But when I turned it on everything seemed to be working perfectly (No screen), fans, hdd, dvdrom all turned on but after like 2-3 seconds it shut itself down and then after like 4-5 seconds it turned itself back On, (fans, hdd, everything was on. It'll stay on until I hold the power button to turn it off.)
But There's no screen (it's like monitor is sleeping), no post, no beep(s)...

System Specs:
Cpu: Core i5 2500k
Mobo: Asus P8P67
Ram: 2x2 Corsair xms
Gpu: Gigabyte 6970 2gb
Power: 685W

I searched the forums to find a solution but all to no avail.

These are somethings I did to try to find the problem:

1.checked every cable, everything seems to be perfectly connected
2.I checked if I plugged NH-C14 fans into CPU_Fan socket on motherboard. (although C14 fans are 3 pins! they aren't pwm, not sure if that's related)
3.Plugged C14 in another socket and plugged the old stock hsf in CPU_Fan just to see if motherboard was detecting a fan signal and didn't automatically shutdown everything.
4.Tried with only one ram stick.
5.Tried with no ram stick (No beep)
6.took out gpu, with ram and no ram (No beep)
7.Checked the Power/Reset switches
8.Tried reseting cmos


I'm really getting desperate and hoping there's nothing wrong with my mobo or cpu... and it's just a simple mistake.

Thank you,
Pooya

October 1, 2012 7:22:07 AM

PSU gone.
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October 1, 2012 8:09:05 AM

proton007 said:
PSU gone.


Oh I'm sooo glad you said that! I mean I'm glad it's not mobo or cpu! :) 
Is there anyway to make sure? (I don't have a spare psu)
It was working perfectly fine until I changed the cpu cooler, weird... how can that happen?
October 1, 2012 9:08:30 AM

I did the Paperclip test and power turned on and stayed on... (fans, hdd and dvd burner were connected)
Does that mean the psu is 100% ok? or maybe when it's using more power like when it's connected to mobo, it would fails?
a b B Homebuilt system
a b à CPUs
October 1, 2012 9:31:15 AM

I believe the PSU is allright. Make sure that heatsink is firmly fastened to mainboard. It's common error when there is not enough pressure and mainboard won't see the cpu.

Paperclip test is not 100% accurate. Your PSU may switch on, but still fail under load.
October 1, 2012 9:41:05 AM

Bejusek said:
I believe the PSU is allright. Make sure that heatsink is firmly fastened to mainboard. It's common error when there is not enough pressure and mainboard won't see the cpu.

Paperclip test is not 100% accurate. Your PSU may switch on, but still fail under load.


I just made sure the heatsink is firmly fastened to my mainboard, I even changed it back to the intel stock cooler.
Right now, my mainboard is on it's box and nothing is connected to it but power cables(both), cpu and hsf. it does the same thing.
I think you are right and psu fails under load that's why I couldn't see anything in paperclip test, but is there anyway to make sure it's psu before I send it to the company (50 month warranty) or buy a new one?
a b B Homebuilt system
a b à CPUs
October 1, 2012 9:44:37 AM

There are professional PSU testing machines that create load on all rails. Call some pc workshops in your area, maybe they will test your PSU for free.
October 1, 2012 11:13:50 AM

Apparently... they don't have a psu tester! lol
October 1, 2012 1:32:53 PM

WhiteRenard said:
Apparently... they don't have a psu tester! lol


Hmm...try another psu?
Because it turns on, then on load turns off, I suspect its PSU.
October 1, 2012 4:12:53 PM

I'm taking my case to a store nearby to test the psu on another pc...
I'll let you know what happens. I hope it's the psu...!
October 1, 2012 6:34:33 PM

So, the problem isn't the psu! I tried another 650w psu and the same thing happened!

p.s. I just remembered something!! When I tried the 650w psu, I didn't connect the 8pin cpu power cable!! Damn! Could this be why the same thing happened with the new psu? I'm gonna try it again tomorrow!
a b B Homebuilt system
a b à CPUs
October 1, 2012 6:46:05 PM

Yes, fans spinning and no post is exactly what should happen without 4/8pin connected.
October 2, 2012 7:20:46 AM

Ok, so now I tried it again (connected both power cables only) and the same thing happened.
I just want to point out the new 650w psu had a 4pin connector instead of 2x4pins. I did a little research on forums and found out that it should be fine to use 4pin on 2500k as long as I'm not doing heavy OCing. (OP had the same cpu and mobo as me)
This is the thread: http://www.tomshardware.com/forum/288400-30-sandy-bridg...

So, what do you think is the problem now? Motherboard or cpu?
October 2, 2012 7:34:30 AM

This was happening to me a while back, it ended up being a bad RAM stick. The make just have the bare essentials connected, cpu, ram, video card and all the power cables, and then report back to us.
October 2, 2012 8:04:06 AM

bluebob951 said:
This was happening to me a while back, it ended up being a bad RAM stick. The make just have the bare essentials connected, cpu, ram, video card and all the power cables, and then report back to us.


I'm sorry I didn't understand your last sentence...
And I did try with and without my ram sticks, but the same thing happened.
October 2, 2012 10:20:46 AM

I'm having almost the exact same problem at the moment, after installing an NH-C14 on an i5-3570k with an Asus P8Z77-v mobo. All the fans and disk drives spool up on booting, but the monitors, mice and keyboard do not light up. The light on the W-LAN aerial socket on the back panel does not light up either. I didnt have much time for troubleshooting last night, but I suspected that I'd knocked the RAM out of place or I'd accidentally ESD'd the mobo

What I did notice on mine is that the MemOK light on the mobo is on. According to the manual this means the RAM is either corrupt, unstable (e.g. after overclocking) or badly seated. So make sure it's seated well, and try another set of RAM chips if you can
October 2, 2012 1:28:25 PM

FlutterGuy said:
I'm having almost the exact same problem at the moment, after installing an NH-C14 on an i5-3570k with an Asus P8Z77-v mobo. All the fans and disk drives spool up on booting, but the monitors, mice and keyboard do not light up. The light on the W-LAN aerial socket on the back panel does not light up either. I didnt have much time for troubleshooting last night, but I suspected that I'd knocked the RAM out of place or I'd accidentally ESD'd the mobo

What I did notice on mine is that the MemOK light on the mobo is on. According to the manual this means the RAM is either corrupt, unstable (e.g. after overclocking) or badly seated. So make sure it's seated well, and try another set of RAM chips if you can


Oh sorry to hear that, I know it's really frustrating.
I did notice that my W-Lan aerial socket light doesn't light up either, same as the mouse and keyboard. The only difference is that my MemOk light only blinks once when I turn on the computer (Red light), I doesn't light continuously like yours do.
Unfortunately I don't have another set of ram to try out, But I did try each one of them alone and on different slots too.
Shouldn't there be some kind of beep if there was anything wrong with ram sticks.
Mine doesn't beep. although I haven't heard any beep from my speaker for a long long time.
October 2, 2012 3:41:44 PM

OK, I've just spent the last 90 minutes swapping out each component and then attempting to boot. Nothing made any difference, until I finally gave in and refitted the stock heatsink. Now it works perfectly again, so the problem definitely lies with the NH-C14. Have a go at doing this too, and report back.



p.s. When I say refit the stock heatsink, I mean physically take out the NH-C14 and put the stock one back in. Don't just plug in the stock heatsink to CPU_FAN without actually fitting it. I tried that too, it didnt work
October 2, 2012 3:55:51 PM

FlutterGuy said:
OK, I've just spent the last 90 minutes swapping out each component and then attempting to boot. Nothing made any difference, until I finally gave in and refitted the stock heatsink. Now it works perfectly again, so the problem definitely lies with the NH-C14. Have a go at doing this too, and report back.



p.s. When I say refit the stock heatsink, I mean physically take out the NH-C14 and put the stock one back in. Don't just plug in the stock heatsink to CPU_FAN without actually fitting it. I tried that too, it didnt work


Oh, that's good news, I'm glad you got your system back! :) 
Although now the question is why C14 was causing your system not to boot, maybe you didn't fasten it very well...

I actually switched back to intel's stock cooler a little after I started experiencing this problem, cause that NH-C14 is HUGE and it was really hard to work around it. So I gave up and changed it back to intel's stock cooler to test everything easier. (it's very well fastened in place)
October 2, 2012 4:05:23 PM

So refitting the stock heatsink didn't fix the problem for you?

I think I'd fastened mine securely. It certainly wasn't budging, although there is the chance I did something wrong since this is the first time I've fitted an aftermarket CPU cooler...
October 2, 2012 4:10:35 PM

FlutterGuy said:
So refitting the stock heatsink didn't fix the problem for you?

I think I'd fastened mine securely. It certainly wasn't budging, although there is the chance I did something wrong since this is the first time I've fitted an aftermarket CPU cooler...


No, it didn't. :(  really made no difference.
I'd say, read the manual again and watch couple of videos on youtube on "How to install NH-C14" then change back to NH-C14 again and see if the problem still persists. did you make sure you weren't shorting anything out? or maybe too much thermal paste?
a b B Homebuilt system
a b à CPUs
October 2, 2012 9:31:09 PM

I think the only thing you can do now is to check all components one by one.
PSU is good, you have to check CPU and mainboard.
Make sure that when trying to boot you have only one stick of ram inserted or even get one that is know to by 100% working.
October 3, 2012 10:10:42 AM

OK, mine is working now. I think the problem was the backplate not being attached firmly enough. Make sure the hex-tipped bolts (for lack of a better way of describing them) are aligned properly, it's very easy for them to slip out of place while you're attaching the nuts. If this happens, then the cooler won't make good contact with the CPU.

Also, don't overdo it with the TIM.


!