Help needed p7p550 pro MB RED CPU LIGHT

Castoraurora · 3 Sep 2011 at 05:57

Hello i recently bought my friends old PC since he upgraded to an I7, he sent me his old I5 750, p7p550 pro MB 750 watt corsair power supply etc via Parcel Force. The parcel itself was very well protected bubblewrap the end polystyrene bits and some of that air bag packaging it came in his new coolermaster haf x case box. When i opened it up for the first time apart from a bit of dust the first thing i noticed was that somehow in transit the stock intel cooler had become displaced and 3/4 pins were unpinned, apart from this there were no obvious signs of damage. I looked at the thermal paste and noticed there was half on the cooler and half on the cpu which was still intact and in its holder, i removed the CPU just to doublecheck being careful not to touch the underside and secured it back into place (im 100% positive i put it back in the right way lining up the arrow). I'd like to add at this point the thermal paste was looking quite dry and brittle as if it would almost peel off. Nevertheless i decided to try and boot to check there was no lasting damage so i pinned in the cooler again as best i could (although ive never actually done one before) and tried to boot. The green power light is on which is a good sign i guess but the CPU light flashes red, all the fans turn on for a brief second then it immediately shuts itself down, and without me pushing the power button again it reboots itself after 3-4 seconds and repeats the process. Some PC literate friends have told me its just the motherboard trying to save the CPU and either theres not enough contact from the heatsink or it needs some new paste. Ive since removed the stock cooler to find 2/4 pins at the bottom have snapped obviously where i tried to fit it back in (yes i know im special). Ive since ordered an aftermarket cooler and a friend will be fitting it, i would just like some reassurance from people that this will likely solve the issue. I'm aware that people may say check the RAM/Flash BIOS and other fancy things but the pc was running not 2 days ago when my friend had it.

EDIT: the red light flashes and is not permanent when the fans stop so does the light.

http://img690.imageshack.us/img690/3926/imag0019lq.jpg

Picture for reference ( since been well dusted )

Any input would be nice and thanks for your time, sorry if i've not given a lot of detail im fairly new to pc's.

Tealc · 3 Sep 2011 at 09:24

Using dry and brittle thermal paste wasn't a good idea. It's never going to fit back into the micro cavities on the cooler and thermal spreader on the CPU so would probably act as an insulator rather than a conductor. You will need to get yourself a tube of any thermal gunk you can find before attempting to refit. The aftermarket cooler should come with a small tube of it, most do.

You may also want to check the CPU pin array on the motherboard for any obvious bent or damaged pins. It's possible that one or two have been pushed by the loose cooler or something. It should be fairly easy to see if there are any out of place when looking down on the array of pins.

I'm somewhat surprised that it cuts off so quick though with a heatsink sitting atop it, unless it isn't fitted so it's touching the CPU of course.

Castoraurora · 3 Sep 2011 at 09:34

Thanks for the reply and the pins were never exposed to the cooler during transit although the cooler itself had come loose the chip was in the socket itself so im guessing the pins were out of harms reach. I wonder if the fact the cooler was obviously moving during transit whether its actually just a broken fan with it being a bog standard intel cooler? thoughts? and yes its literally 3 seconds turns off and about another 3 turns on and repeats

Found this video which is exactly whats happening

http://www.youtube.com/watch?v=SjR58Tj07fo

Tealc · 3 Sep 2011 at 09:56

If the fan were broken you'd be able to tell because it wouldn't spin up at all.

Could be the same issue as in that video but it's odd that the motherboard was working just a couple of days previously.

So the cooler was loose. If it was only retained on one pin then it has quite a bit of travel it can do around that single pivot point. It could have smashed into a capacitor or a mosfet, an integrated circuit or a transistor and shorted out or damaged something.

It's usually advisable to remove coolers from the CPU when in transit unless a method can be found to pack the cooler rigidly in place. Even an Intel cooler weighs a fair bit.