Abit KT7A Northbridge Fan Warning

[TC]

This may be a little out of place, but for any fellow Seti crunchers with an Abit KT7A I wanted to issue a word of caution. Tonight I found my 3rd failure on the northbridge cooler - the fan quit once again. I've had three KT7A's and each has suffered a fan failure on the northbridge HSF. I didn't catch it right away. All three machines were happily overclocked for quite a while, then each one started crashing. They were no longer happy at the speed they had been running for weeks. I bumped them down, only to find they would barely handle default speeds. I thought perhaps the chips were dying from being overclocked. Each turned out to be a stalled fan on the northbridge. Abit seems to be using a very cheap fan. It's easy to overlook, but if you're having weird stability problems look at that little fan. The one I found tonight was literally turning about 5 rpm. It had failed once before, but a little nudge got it going again. This was the only thing that reminded me to look at it.

[chawken]

Originally posted by TC
This may be a little out of place, but for any fellow Seti crunchers with an Abit KT7A I wanted to issue a word of caution. Tonight I found my 3rd failure on the northbridge cooler - the fan quit once again. I've had three KT7A's and each has suffered a fan failure on the northbridge HSF. I didn't catch it right away. All three machines were happily overclocked for quite a while, then each one started crashing. They were no longer happy at the speed they had been running for weeks. I bumped them down, only to find they would barely handle default speeds. I thought perhaps the chips were dying from being overclocked. Each turned out to be a stalled fan on the northbridge. Abit seems to be using a very cheap fan. It's easy to overlook, but if you're having weird stability problems look at that little fan. The one I found tonight was literally turning about 5 rpm. It had failed once before, but a little nudge got it going again. This was the only thing that reminded me to look at it.

Yes, they are not the best fans in the world. A while back I read an article about modifying the blue orb for the chipset. I have several KT7A's, all using a blue orb for the chipset cooler - with of course ASII.

[M@€$†®Ö™]

What alternatives for the North Bridge are there ? I think its a good warning you shared TC.

Maestro

[chawken]

Originally posted by Maestro
What alternatives for the North Bridge are there ? I think its a good warning you shared TC.

Maestro

The blue orb is great for cooling the North Bridge. As it is, unmodified, it does not fit - but it takes only about 5 minutes and a dremel and it will fit. Or you could epox it with Artic Silver epoxy and that also works.

[M@€$†®Ö™]

Thanks I will check into it. Does anyone know the MTBF of the North Bridge Fan ? From what I am gathering its only a few thousand hours or so.

Maestro

[TC]

Have no idea what it's rated at. I looked up the company that makes the fan and found very few specs. I was in a rush to fix mine, so I found an indentical size fan that came out of a hard drive cooler bay I once had. I unscrewed the bad fan and put the new one on and I think it may be better than before. This evening I was tinkering with the fan that died, and I actually fixed it. It's a brushless fan, so oil won't hurt it. All I did was squirt some WD-40 in the back and it smoothed up. Seems whatever it has for bearings had gotten dirty and that caused it to seize. Might be an easy fix if this ever happens to yours. Just make sure you clean the excess oil off before putting it back in service. I wonder if anybody makes a high quality fan with ball bearings?

[Morpheus]

Sunon makes EVERY kind of fan.. just finding a vendor for it... LOL...

[M@€$†®Ö™]

TC your brought up a good issue. Everyone pays attention to the cooling of the CPU. But there are other components just as crictical or so I think. And the north bridge is one of them. I plan on trying to get some serious cooling on it. Reason for s if you overclock everything is overclocked and every part needs to be tip top. I wonder if a adapter of some sort could be used and use a Delta on the North Bridge. I know Overkill but its a exercise in eliminating doubts :)

Maestro

[TC]

Originally posted by Maestro
TC your brought up a good issue. Everyone pays attention to the cooling of the CPU. But there are other components just as crictical or so I think. And the north bridge is one of them. I plan on trying to get some serious cooling on it. Reason for s if you overclock everything is overclocked and every part needs to be tip top. I wonder if a adapter of some sort could be used and use a Delta on the North Bridge. I know Overkill but its a exercise in eliminating doubts :)

Maestro

You're right. The northbridge on most new boards gets quite hot. In fact the cooling on most of these is very poor compared to what we do for our cpu's. Usually I cannot leave a finger on the heatsink of a stock northbridge cooler. They literally get hot enough to burn you. Put your finger on the cpu heat sink and you're likely to feel slight warmth. I even remember going to great pains to cool the PLL-IC - the system clock generator. I remember some getting smoking hot. My Asus P3BF was hot enough to burn almost instantly. Cooling that chip alone got me a few extra MHz higher. Seems to me that cpu cooling has taking the spotlight lately, while other important components get a take a back seat. If you want to overclock to the max and remain stable, everything needs to stay cool.

[MiteyJoe]

Originally posted by Morpheus
Sunon makes EVERY kind of fan.. just finding a vendor for it... LOL...

www.jameco.com (http://www.jameco.com) carries just about every sunon fan i can think of.. plus a few others. =)

also, you might want to check out www.mechatronics.com (http://www.mechatronics.com) they are a manufacturer of fans, and they specialize in ball-bearing, high CFM, high pressure fans.

-Joe-

[TC]

Thanks for those sources. Both look like great companies.

[M@€$†®Ö™]

Hey TC when you get some spare time. Could you post up what components you think warrant the most cooling. Just trying to sort out my priorities on how to get the tidbits cool I am serious considering getting adaptes for some things and using a bigger fan with a downsize adapter to it. Thanks for your input and help its much appreciated.

Maestro

[TC]

Originally posted by Maestro
Hey TC when you get some spare time. Could you post up what components you think warrant the most cooling. Just trying to sort out my priorities on how to get the tidbits cool I am serious considering getting adaptes for some things and using a bigger fan with a downsize adapter to it. Thanks for your input and help its much appreciated.

Maestro

Sure...I would say first priority goes to the cpu - certainly with Athlons. The new P3 Tualatins I've got hardly even need a heat sink. In fact when I first got them I failed to notice that the fan's power cord had snagged a blade and the fan had not been running for nearly fifteen minutes. I freaked out and pulled the power cord, only to find the heat sink moderately warm to the touch - absolutely amazing. Moving along, number two would be the northbridge, especially on the DDR boards. The little blue orbs are good, as well as the lsagna cooler that Joe likes to use. After this it's probably a mixed bag as far as what else needs to be done. On the Athlon boards the mosfets in the regulator circuit tend to get very hot, even with heatsinks. What I do is aim a fan directly at them. The pll-ic gets fairly hot on some boards, but some of the newer boards don't seem to be affected. If it is getting warm it could affect the quality of the clock signal being sent to the board. The old Asus P3BF was a smoker. I modified a passive heat sink from a video card and glued it on with thermal epoxy, and I believe that earned me another two or three MHz as far as FSB goes. I guess that's about it. One of the best things in general is good case ventilation. Cooling the back of the board helps too. Some cases have enough room to cut a hole in the mounting plate and secure a fan that sucks air from underneath the board. I guess it all depends on how far you want to go, but certainly every little bit can't hurt.

[M@€$†®Ö™]

Thank You TC ! You support my thinking entirely and your input was very helpful to me. I just wanted to say from me to you personally your knowledge is invaluable and welcome as I learn everyday and I do this stuff for a living. Again thank you ! In closing my other question is what type of cooler you use for the North Bridge and The Other components you mention. I am considering going overkill on everything and do some testing and see what yield I might gain. I have a KT7A and KG7 boards. KT7 with a 650 @ 1050 to 1100 depending on ambient temps and the KG7 with a Palo 1.2 @ 1.4. And for giggles I took my Duron down to 500 mhz running at 1.1Vcore 650 mhz @ 1.25 Vcore Even under full load it stayed below system temp. Kinda interesting..

Maestro

[TC]

For chipsets I like the TennMax lasagna cooler that Joe has mentioned. Here's a link: http://www.tennmax.com/lasagna.htm

Use arctic silver epoxy to secure the cooler. For the pll-ic those little greenies are great. You almost always have to cut out a notch to clear the quartz clock in the oval tin can next to the ic. Use a dremel tool or whatever you have. Secure the sink with silver epoxy. Aside from that good air flow is the best thing you can have in your case. Rig up a fan mount to blow against the board. This helps move heat away from the other components and carry it out.

Glad to help out. I do this for a living too, and I never stop learning. I don't think it's possible to know everything about computers as a whole. I think this is another reason we have such a great team. We help ourselves grow stronger and faster.

[M@€$†®Ö™]

TC thank you again ! I am going to really dig into this. I was planning on doing a total overhaul of the system with rounded cables, tons more air flow and the ideas you threw at me. I checked out the Lasagna Collor very small and efficient package. Definitely a must to get with. If you get the notion could post up some pics if you have done any of the cooling to your KT7A. Just need reference out how and what you did so I can cut down on my learning curve. If not no biggie. Thanks Again. I am amazed they did not move this thread to AMD mobo or Cooling :D

Maestro

[TC]

Here are a couple pics of my KT7A. I'm using a 172-watt TEC cooled with a Swiftech kit. I was very disappointed with the results. The cpu hovers around 65 to 70F under load. The water block alone could have maintained 70. I’ve tinkered with it a lot and couldn’t squeeze anymore out of it. The radiator works fine, and I’ve got plenty of water flow. Discharge temp on the radiator is usually 75F under load. The peltier is on its own 300-watt psu, which you can see mounted in the bottom 5.25 bay. The northbridge doesn’t get terribly hot on this board, but I did put an over sized fan on it. The pll-ic doesn’t require cooling on this board. I’m getting ready to pull this board and put in a tusl2 with the P3S. This board was cranking out units in the 5 to 6 hour range, and the P3S will cut that down to just over 3.

http://home.earthlink.net/~jskinlaw/back.jpg

http://home.earthlink.net/~jskinlaw/inside.jpg

[TC]

Bump for Maestro.

[M@€$†®Ö™]

TC I got your Pm. Thanks for posting up the PICS. I downloaded them and I am going to study them. Took a long labor day weekend off and relaxed :) Again thanks for your help.

Maestro

[killem1x1]

Man that looks awsome, what did you use to "seal" everything?

[TC]

Originally posted by killem1x1
Man that looks awsome, what did you use to "seal" everything?

Swiftech provides a fairly complete gasket set that's cut to fit everything in the kit. The center of the socket was filled with silicone, and a foam pad goes underneath the socket on the back of the board. I forced non conductive grease into the socket's holes. That pretty well stopped all the water. Just in case I masked the core of the cpu and sprayed the bridges with a silicone conformal spray. It has run for about 5 months 24/7 and I just took it apart a few days ago. There was no evidence of condensation at all, but one of the pins fell off the cpu - so who knows, maybe it did get wet.