Replacing CPU Fan

LMTC · Mar 12, 2007

OK, I use the PC to surf the net and visit bynet, so this is "related", right?

I'd appreciate any guidance from those who have done this. Older PC, Athlon 2200+, I am pretty sure I ordered the correct item....a CPU Fan/heat sink compatible with socket A (per my mobo's specs, that seems correct...Biostar M7VIQ). I also ordered 3.5 grams of Arctic Silver 5 thermal paste.

CPU fan is making an uncool grinding sound on startup, usually clears up in a minute or so. I have put in case fans, RAM, and a few drives, but this I have not done. I removed the fan once to look it over, the heatsink stayed. As I understand it I should replace both with the new fan and heatsink. When I remove the fan (4 screws into heat sink), will the heatsink be held in place with screws too? Is there a thermal pad to remove? Old thermal paste? How is this best removed?

What is the procedure for installing the new thermal paste? A very sincere thank you for any guidance.

Tig · Mar 12, 2007

I think this article should be helpful.

How to apply thermal paste to your AMD Athlon XP CPU (Barton) « oneduasan

Tig · Mar 12, 2007

After a closer glance I don't like the amount of paste the guy uses in the link I posted. I think he used far too much. He does have lots of other good info there.
Wipe the old paste off with a lint free cloth. Use much less paste than the guy did in the link. I've heard that you should use a dab about the size of a grain of rice (cooked). I would suggest you take a picture of what the paste spot looks like when you remove the heat sink. Clean the heat sink and CPU. Put a dab on and reinstall the heat sink. Remove the heat sink to compare the result to what you see in the pic you just took. Did it cover a reasonable size area? Clean it off and try again, adjusting as necessary. When you think you have it right don't take it off to look at it. You just want get reasonable coverage and avoid having it gush out the sides.

LMTC · Mar 12, 2007

Thanks, that was helpful. Is there a consistent way in which heat sinks "attach" or does that vary? Should I screw the fan to the heat sink after the heat sink is installed over the paste?

texbaylea · Mar 12, 2007

I woul expect that the new fan and heat sink would come as one assembly and be held on to the MB/CPU socket by clips. At least that is the way mine have been.

Vernon

Mickey_Fx · Mar 12, 2007

The link Tig offered seems fairly decent and agree with Tig the amount of paste is more than I typ use. You do want to insure the paste covers 100% of the cpu but not overdo the paste.

I typ make sure there is a small amount of paste protruding from the top of the tube then I touch the end of the tube to the CPU so it transfers a small amount of paste. I'm not too concerned about a little bit of the paste seeps out beyound the edge of the CPU but I don't want a large amount showing up there. I've never had a problem with heat due to application of paste.

NO need to remove the old fan from heatsink if it is an OEM or sim fan/heatsink design. You need a good mid-sized blade screwdriver to remove the spring clip that secures the heatsink to the CPU mount. DO pay close attention to the raised edge of the CPU mount and not let the heatsink ride on it. This would prevent the heatsink from being seated properly. This is mentioned in the link instructions but I like to place additional importance on this. After the heatsink is secured take a close look to make sure it is seated flatly on the CPU itself.

Tig · Mar 12, 2007

I'm not really up on my socket identification but from the pics I think the clip that holds the heat sink is released by piching the sides of the heat sink. The picture of the heat sink install shows the clips. Note: This site says the heat sink can only go on one way or damage may occur.
Here is the paste instructions from the Artic 5 site.
Arctic Silver Incorporated - Arctic Silver 5 Instructions
They say to use an amount equal to 1/2 a grain of uncooked rice.
Fan should be on heat sink when installed.

LMTC · Mar 12, 2007

Ah, but I love the compendium of talents available here. Thank you.

OK, I stopped my newegg order to digest all this material. Anyone have any favorite manufacturers, or any to avoid?

I also use a PC with Athlon 64 dual core processors, and while the fan is not acting up, the machine tends to run hot. I am not averse to spending money when it benefits me, and it seems perhaps I should buy a better cooling system for this PC while I'm at it. It currently has an 80mm fan over a heatsink. It is listed by HP as a Socket 939. I have found a Zalman 9500 listed at newegg for socket 939, but the heatsink is 85mm and the fan 92mm. Must I find an 80mm unit? Any opinions as to whether Zalman is worth the $$?

California · Mar 12, 2007

LMTC said:
Athlon 2200+ ... CPU fan is making an uncool grinding sound on startup, usually clears up in a minute or so.

I just did one. Athlon 2400, Socket A. I simply replaced the fan. It's quiet now.

Ebay: 70x15mm Heatsink Fan. He mailed it immediately. Total cost $5 including postage.

RobertN · Mar 12, 2007

Tig said:
After a closer glance I don't like the amount of paste the guy uses in the link I posted. I think he used far too much. He does have lots of other good info there.
Wipe the old paste off with a lint free cloth. Use much less paste than the guy did in the link. I've heard that you should use a dab about the size of a grain of rice (cooked). I would suggest you take a picture of what the paste spot looks like when you remove the heat sink. Clean the heat sink and CPU. Put a dab on and reinstall the heat sink. Remove the heat sink to compare the result to what you see in the pic you just took. Did it cover a reasonable size area? Clean it off and try again, adjusting as necessary. When you think you have it right don't take it off to look at it. You just want get reasonable coverage and avoid having it gush out the sides.

Wipe the old stuff off with a clean cloth; don't get the grease on you(won't hurt, just messy). Once the bulk of it is off, wipe both surfaces with a clean rag and a litle alchohol.

Put a dab of grease on there. A dab the size of cook rice is ok, two grains of rice is fine. Too little grease will not give the thermal conductance needed. Too much grease, will just ooze out the side of the heatsink. Won't hurt anything, although it can make a little mess to clean up if you have doo it again.

Dabbing somegrease on, replacing the heatsink, and then pulling it off to check the spread of grease is unreliable. Most grease needs to heat and flow across the heatsink and cpu. All clamping the heatsink does it squish the grease around a little.

Best is to make a note of your heatsink, fan, and CPU. Then try to get the grease specific to that setup. Different grease is used for high power/heat CPU's than in lower power/cooler running CPU's. Grease aint just Grease...

Tested 100's and 100's of CPU/fan/heatsink combo's at my old job. You do want to get the right grease for you combo. And, you do not want to use too little. Before we tested for thermal performance, we let them soak(powered the pc up, and ran it to warm the CPU and heatsink) at a lower performance setting before really pushing them. The difference in the grease spread between application and after stressing the parts was significant.

The grain or two of cooked rice is a good comparison, and should get you in the ballpark. I'd lean towards two grains at least.