hot southbridge on asus a7n8x-x - cooling?

[Clemens von Musil]

Hi all,

I am running an asus a7n8x-x board with an athlon xp 2400+ and three ultra
ata 133 hard disks.

The system hangs from time to time (total frozen, have to reboot), and I
recognized, that the southbridge (nvidia2 mcp) is very hot. I have no
precise sensor, but the chip is REAL fingerburning hot. Must be over 55
degrees.

Since southbridges normally are cool chips, I wonder if the nvidia2 chipset
is hot, or if only MY southbridge is that hot.
And I wonder how to cool this chip.

Thanks for any idea,
Clemens

 

[Chris Stolworthy]

Hi all,

I am running an asus a7n8x-x board with an athlon xp 2400+ and three ultra
ata 133 hard disks.

The system hangs from time to time (total frozen, have to reboot), and I
recognized, that the southbridge (nvidia2 mcp) is very hot. I have no
precise sensor, but the chip is REAL fingerburning hot. Must be over 55
degrees.

Since southbridges normally are cool chips, I wonder if the nvidia2 chipset
is hot, or if only MY southbridge is that hot.
And I wonder how to cool this chip.

Thanks for any idea,
Clemens

Thats odd that it is that hot. I personally have never had one that got
that hot. My board (asus A7n8X) doesn't get even NEAR that hot. ANyway I
would try installing a passive heatsink to it and see if that helps.

 

[kony]

Hi all,

I am running an asus a7n8x-x board with an athlon xp 2400+ and three ultra
ata 133 hard disks.

The system hangs from time to time (total frozen, have to reboot), and I
recognized, that the southbridge (nvidia2 mcp) is very hot. I have no
precise sensor, but the chip is REAL fingerburning hot. Must be over 55
degrees.

Since southbridges normally are cool chips, I wonder if the nvidia2 chipset
is hot, or if only MY southbridge is that hot.
And I wonder how to cool this chip.

Thanks for any idea,
Clemens

nVidia southbridges do seem to run hotter than other makes, hot enough
that some manufacturers put 'sinks on those southbridges. I can't guess
whether your specific southbridge is atypically hot, though if your case
has inadequate airflow or high ambient room temp then it would be even
more necessary to add a heatsink.

A heatsink could be applied with thermal tape, for example "3M Thermal
Tape 9885" (5 mil),
http://www.3m.com/us/mfg_industrial/adhesives/oldadh/html/thermalcond.jhtml
or a thermally conductive epoxy like this:
http://www.arcticsilver.com/arctic_alumina_thermal_adhesive.htm

Of the two methods, the thermal tape is plenty secure enough a bond but
for even slightly good thermal transfer it requires a very smooth heatsink
base, and usually even lapping the southbridge itself (typically the
north/southbridge are concave with an outer "lip", raised area, in
addition to being slightly textured). On the plus side, the heatsink
could later be (carefully) pried off.

The thermal epoxy is the better choice IMHO. It's quite permanent (do not
try to later pry off the 'sink) but much better conductor and it's not so
necessary to lap the 'sink or chip. It goes for about $7 online, but if
you can accept somewhat lower performance you'd probably be fine applying
a VERY thin layer of just about any thermally-stable epoxy, of which
there are many at the local hardware or superstore. I usually use the
thermal epoxy but sometimes I'll get out a tube and it will have gone bad
(not a long shelf life) so I'll use JDWeld Kwik Epoxy in a pinch, which
seems to do just fine for these lesser-heat chips (I'd never use it on a
modern video card though).

Then just find a small enough heatsink... you might have an old one lying
around or be able to buy one for ~$1 at one of the various electronics
surplus 'sites on the 'net.

 

[John]

nVidia southbridges do seem to run hotter than other makes, hot enough
that some manufacturers put 'sinks on those southbridges. I can't guess
whether your specific southbridge is atypically hot, though if your case
has inadequate airflow or high ambient room temp then it would be even
more necessary to add a heatsink.

A heatsink could be applied with thermal tape, for example "3M Thermal
Tape 9885" (5 mil),
http://www.3m.com/us/mfg_industrial/adhesives/oldadh/html/thermalcond.jhtml
or a thermally conductive epoxy like this:
http://www.arcticsilver.com/arctic_alumina_thermal_adhesive.htm

Of the two methods, the thermal tape is plenty secure enough a bond but
for even slightly good thermal transfer it requires a very smooth heatsink
base, and usually even lapping the southbridge itself (typically the
north/southbridge are concave with an outer "lip", raised area, in
addition to being slightly textured). On the plus side, the heatsink
could later be (carefully) pried off.

The thermal epoxy is the better choice IMHO.

I agree with this. Ive been having that recurring problem with an old
Kt133a Asus board after the northbridge heatsink fan died. Its hard to
find an easy way to attack any new heatsinks to it. Each time I think
Ive solved it as Ive posted - it causes the classic freezes as this
poster mentions.

One thing - Im talking abouyt the northbridge not the southridge but I
wondered how hot the thing got so I ran it without a heatsink - just
booting it up and putting my finger on it. That thing gets HOT ! I
can see why it freezes. I cant believe they put those little cheapo
heatsink fans on it. Sure it probably doesnt get near the CPU but wow
it was rapidly approaching the point of being uncomfortable for my
finger. I switched it off right after that.

Ive been putting bigger and bigger heatsinks on it but the thermal
tape is the problem. Its almost impossible to put on flat. Its stick
on both sides obfviously - you take the covering off one side easy but
the other side is almost impossible to take off. You stick it on the
chip or heatsink and try to peel off the other side and its impossible
not to mash it up and tear up the tape its so soft and thin.

After 4 tries I gave up. It wouldnt cool the thing enough either and
thats after moving to a blue orb type cooler which is way way way more
powerful than those little dinky fans it comes with.

I finally tried what others have posted - you put thermal grease in
the middle and superglue at the edges. So far - knock on wood - it
seems to be working great. Obviously if you can get thermal epoxy use
that instead. Around here its $25 a tube at the one place that stock
it and shipping here is $20 and the motherboard is fairly ancient so I
decided to experiment.

 

[~misfit~]

Hi all,

I am running an asus a7n8x-x board with an athlon xp 2400+ and three
ultra ata 133 hard disks.

The system hangs from time to time (total frozen, have to reboot),
and I recognized, that the southbridge (nvidia2 mcp) is very hot. I
have no precise sensor, but the chip is REAL fingerburning hot. Must
be over 55 degrees.

Since southbridges normally are cool chips, I wonder if the nvidia2
chipset is hot, or if only MY southbridge is that hot.
And I wonder how to cool this chip.

I have a Soltek SL-75FRN2-L nForce2 Ultra 400 mobo and my southbridge was
getting quite hot. Certainly too hot to keep my finger on for more than a
second or so. I stuck a HS on that was supposed to be for a northbridge, it
is too big but there are no components around that got in the way. It had
thermal tape already on it. I don't have a fan on it, it gets warm so the
heat is being transfered through the tape, something I had my doubts about.
I've never used thermal tape before and actually didn't (and don't) like the
look of it, it doesn't seem a very efficient medium for heat-transfer.
However, I've used thermal epoxy in the past and regretted it.

(I have a Tualatin CPU and the only mobo I had that would run it had the tab
broken off the socket so I glued the HS to the CPU, off-set so I could get
to the ZIF socket arm. It worked Ok for a while then the mobo packed up. I
found another mobo to run it in but it has capacitors close to the socket
and the HS won't allow me to put the CPU in the socket. One useless CPU now)

 

[kony]

(I have a Tualatin CPU and the only mobo I had that would run it had the tab
broken off the socket so I glued the HS to the CPU, off-set so I could get
to the ZIF socket arm. It worked Ok for a while then the mobo packed up. I
found another mobo to run it in but it has capacitors close to the socket
and the HS won't allow me to put the CPU in the socket. One useless CPU now)

'Tis nothing a hacksaw can't fix ;-)
Umm, not sawing off caps, I meant a part of the 'sink where it hits the
caps on the board.

On the other hand, the heat spreader is held down by a type of silicone
cement IIRC, and it's possible to detach the spreader from the CPU by
cutting through the cement and gently prying up (to free the spreader
since the same cement also glues the core to the middle of the spreader...
just be careful not to cut too deeply yet to cut all of it before gently
prying, I don't recall if there are SMD chip-caps on top of the Tualatins
or not.

OK, found a pic, no caps on top:
http://www.geocities.com/_lunchbox/remove_integrated_heat_spreader.html

Another possibility if the caps are short enough is to remove them from
the front of the board and mount on the back, drilling holes through the
motherboard tray as needed to provide the extra clearance. Or, if you can
get ahold of some Sanyo OS-CONs, you might find a workable cap that's
short enough to fit in the space under the 'sink.. some are <= 10 mm
tall, but unfortuately I have no idea where to find OS-CONs near you.

 

[~misfit~]

'Tis nothing a hacksaw can't fix ;-)
Umm, not sawing off caps, I meant a part of the 'sink where it hits
the caps on the board.

On the other hand, the heat spreader is held down by a type of
silicone cement IIRC, and it's possible to detach the spreader from
the CPU by cutting through the cement and gently prying up (to free
the spreader since the same cement also glues the core to the middle
of the spreader... just be careful not to cut too deeply yet to cut
all of it before gently prying, I don't recall if there are SMD
chip-caps on top of the Tualatins or not.

OK, found a pic, no caps on top:
http://www.geocities.com/_lunchbox/remove_integrated_heat_spreader.html

Hey, thanks for that. It hadn't occured to me to remove the IHS. I don't
have the alternate board now, I let it go as I figured I couldn't use it.
Still, handy to know. I used Zalman thermal epoxy to stick it on. Man that
stuff *works*. I'm thinking it may be possible to remove the IHS from the HS
once it's removed from the CPU as well, it's a damn good HS/F assembly, I'd
like to be able to use it again.

Another possibility if the caps are short enough is to remove them
from the front of the board and mount on the back, drilling holes
through the motherboard tray as needed to provide the extra
clearance. Or, if you can get ahold of some Sanyo OS-CONs, you might
find a workable cap that's short enough to fit in the space under the
'sink.. some are <= 10 mm tall, but unfortuately I have no idea
where to find OS-CONs near you.

That's a bit much for me to do. I've tried replacing caps before and I don't
have the correct tools and I'm not sure if I have the skills.

Hey Dave, a question for ya. I'm looking to replace that PSU that has a low
3.3v and I've come across a AcBel 400W PSU. Quite a bit cheaper than a
Thermaltake 420W and it's supposed to be good, a genuine 400W, but I can't
find much about them. They have a lifetime warranty. Do you have any
knowledge of them? All I've found is their website where they say they've
been making PSUs for 20 years, supplying to IBM, Apple, HP, NEC etc. but not
much in the way of user reviews.

Cheers mate,

 

[kony]

Hey Dave, a question for ya. I'm looking to replace that PSU that has a low
3.3v and I've come across a AcBel 400W PSU. Quite a bit cheaper than a
Thermaltake 420W and it's supposed to be good, a genuine 400W, but I can't
find much about them. They have a lifetime warranty. Do you have any
knowledge of them? All I've found is their website where they say they've
been making PSUs for 20 years, supplying to IBM, Apple, HP, NEC etc. but not
much in the way of user reviews.

My knowledge of them is only about as much as you've already written, that
they supply several OEMs and have the lifetime warranty. I've never had
one except for an external power brick or two and a couple in IBM Netvista
cases, which hardly apply as they're quite a small and proprietary shape.

My gut feeling is that they're decent, no frills but worth their rated
wattage.

 

[~misfit~]

My knowledge of them is only about as much as you've already written,
that they supply several OEMs and have the lifetime warranty. I've
never had one except for an external power brick or two and a couple
in IBM Netvista cases, which hardly apply as they're quite a small
and proprietary shape.

My gut feeling is that they're decent, no frills but worth their rated
wattage.

Thanks.