accidentally removed the heatsink

[jcoverload]

Hi, first time here, and I have a problem. Big surprise. lol

Anyway, so this is what happened...
I really needed to clean the fan that was attached to the heatsink, so I got my screwdriver and started to unscrew what I thought was the fan. I've done this on my main computer several times, so I thought I knew what I was doing.  Well, I accidentally removed the heatsink from the CPU instead of just the fan. When the screws loosened, it just fell away from the CPU, like it wasn't attached by the paste at all. When I realized what I did, I immediately screwed it back together.  Now, it won't power up unless I hold the power button. The power lights come on, all 4 fans (psu, 2 rear, 1 CPU) all start up, but it won't stay on and I don't hear it accessing any of the drives or anything. Could it be that I just need to reapply thermal paste? Of all the times I've messed around inside of a computer, one thing I never touched was the heatsink/CPU so I'm not exactly sure what kind of problems can arise from doing that. Any info would be greatly appreciated. Thanks

[Dias de verano]

What motherboard? What cpu? What fan? What brand/model computer?

The paste is not meant to be a glue for the heatsink, so it's no surprise that a heavy heatsink would fall off. (You had the motherboard vertical when you were doing the unscrewing?) Have you checked for unseated cpu or damaged/bent pins?

[jcoverload]

gateway emachines intel p4 504GR  skt 775
Augsburg 915G Motherboard w/ PCI & 1394 4000966


Yes I had it vertical, I was just quickly trying to remove the fan, not the heatsink. It was stupid, I know. No damaged or bent pins. It happened really fast, it didn't hit the bottom of the case, and as soon as I noticed I had the heatsink and not just the fan, I positioned it back and screwed it back in, however, I did do this vertically. When it didn't start up properly, I positioned it horizontally and loosened the screws and tightened them up again, but that didn't solve the problem.

[Dias de verano]

Sorry

It's a gateway intel p4 504GR

If it is like the picture, with a standard P4 cooler, then the fan is an integral part of the retention frame over the top of the heat sink. The screws that you undid hold the mounting frame onto the motherboard.

Have you done these things?

- examined the cpu for bent or damaged pins

- cleaned off old thermal compound from cpu and base of heatsink

- applied new thermal compound

- checked that heatsink frame is properly screwed down

- reassembled heatsink to frame and properly closed retention clips, avoiding excessive bending of motherboard

- checked motherboard for cracks or damage to mounted components caused by heatsink falling off

- checked fan power lead is connected (if not, the motherboard will probably refuse to power up the cpu)

You need to do these things, and if you don't feel confident, then a repair shop may be a good idea.

[jcoverload]

Dias de verano,

No, that's not the one...this is what it looks like...


http://www.skyline-eng.com/index.cfm?fuseaction=product.display&Product_ID=6160
the top part is the shroud, but there is nothing else holding the heatsink on besides the 4 screws that hold it to the motherboard, which is how I managed to remove it without intent.


I don't normally tinker around with my CPU's/heatsinks, so I don't keep thermal paste handy. I'll be heading out to get some tomorrow.  I could see that the old stuff was definitely dried and crusty.

I just want to understand if this situation is plausible and not extraordinary (that if a heatsink is loosened from a CPU and the paste is old, the computer will likely not power up properly?) 

Thanks
lisa

[Dias de verano]

I just want to understand if this situation is plausible and not extraordinary (that if a heatsink is loosened from a CPU and the paste is old, the computer will likely not power up properly?) 

I don't think it is plausible. If those were the only things that were incorrect (loose heatsink, old paste) then the computer would boot up; however the cpu would get rather hot in a short time*. Depending on how good the thermal contact was between the cpu and the heatsink, this could be seconds or minutes. However you would definitely see signs of the computer booting up as opposed to the dead PC you seem to have.

* If you did not shut down fairly quickly you would see and smell smoke and thereafter would need to buy a new CPU.

[ghaldos]

The paste (thermal grease) isn't there to hold it onto the cpu but rather to minimize the space between the cpu and heatsink as well as to distribute the heat a little better and yeah the heatsink not being on correctly is the cause of it, at that point the thermal grease will do nothing to help it. When a cpu can't be properly cooled to prevent from overheating and frying itself as with many older cpus, there was a sensor put in so that when it reaches a certain temp it will cut off power going to it. Just having the computer on it's side allowing only gravity holding it in place won't be enough you have to have it tightly against it using the screws. Having said that good luck they're just annoying to get on.

[Dias de verano]

and yeah the heatsink not being on correctly is the cause of it

I do not agree; the cpu would not heat to the shutdown point instantly. The OP's system does not even POST. I have run a cpu (accidentally) with a loose heatsink; the PC booted normally but reached an excessive temperature after about 2 minutes.

[ghaldos]

depends on the cpu really.

[Dias de verano]

depends on the cpu really.

This was a Prescott core P4, well known for heat production and rapid increase in temperature. Please name at least one processor that can heat to shutdown temp instantly. Or leave us to draw the natural conclusion.

[ghaldos]

the heatsink for these are like a quarter of the case, I've encountered the same problem with a cpu that uses this type of heatsink. Screw the heatsink in right and test it out it's always good to test things before running out and spending xxx amount of dollars only to find out that whatever wasn't the problem.

Dias I see that you don't agree and really was no need to get back solely for that purpose the guy can test this out see if it works if it does great and if it doesn't then you go on to the next thing, it's about trial and error. There is probably a reson why the heatsink is like quarter the size of the case, and yes I know it's not a literal quarter of the case I'm just exagerating to prove a point. Also it only started doing it AFTER he removed the heatsink so he either shorted out the cpu by a static charge (unlikely) or the heatsink isn't right.

[Dias de verano]

The Op has been gone for 1 week now.