Cooling an Apollo 1240 in the A1200 case (reloaded!)

[8bitbubsy]

Yes, this time I mean it for real!
There are probably a few threads out there for this, but this one is meant to really bring a nice idea out there to people with the same problem.

So you might be one of those that does have an Apollo 1240 or 1260, but an old revision of the CPU - what does that mean? Well, it means that the CPU will most likely get very hot and reset the Amiga 1200 just when you try enjoy watching a cool demo. For me, I can toy with my A1200 for about 40 minutes before I get a reset, then everything is unstable... It all depends on how much CPU load I have got, obviously :-)

The problem is that there is almost no room at all for a heatsink! Any good ideas? There's no room for a fan either (well, *only* a fan would fit, but would cooling the die itself help any good..?) I currently use an XC68040RC40 in my Apollo 1240, underclocked to 25MHz. Yet it gets hot as a scorcher then reboots the Amiga!
I've yet not found any heatsink so thin that it will fit in the middle of the CPU without crashing with the keyboard... A dude on here sent me a thin heatsink and a fan, but no luck.
Speaking of CPU revisions, I also have an MC68040RC33 from around 1998, but that one refuse to work with the Apollo. Blank screenie all the time.
I have two other 060s, but none of them works either (with voltage regulator, two different boot ROMs, and a lot of jumper testing).
(in case you wondered, I use a healthy 300W PSU with very good voltage ratings, it's not that)

Any hackery tricks and tips accepted! Can I use some sort of thin copper to make the heat less concentrated?
I can't stand that my fastest Amiga accelerator is unusable in the A1200 case...

[zipper]

Just a fan blowing on the die is better than nothing - I've done it for my 060 just to make it's life a little more comfortable (CSPPC and Blizz 2060).

[rkauer]

A lower enough heatsink and a vertical fan a bit far from the 040 will do wonders for it.

[dabone]

Here's what I did for my 040/40mhz.

http://www.amibay.com/showthread.php?t=4986

Works quite well. I haven't been using it latley, but it ran for hours running games and demos with the bottom cover on with this solution.


Later,
dabone

[Hewitson]

An 040 must have a fan. Its as simple as that.

Re the 060 not working, you got a Mach 131?

[8bitbubsy]

Originally Posted by Hewitson

An 040 must have a fan. Its as simple as that.

Not the later mask ones.

Originally Posted by Hewitson

Re the 060 not working, you got a Mach 131?

Yes I do.

[Hewitson]

You argue with me, yet your machine shuts down all the time due to overheating.. Work that out..

[stachu100]

Originally Posted by 8bitbubsy

Any hackery tricks and tips accepted! Can I use some sort of thin copper to make the heat less concentrated?
I can't stand that my fastest Amiga accelerator is unusable in the A1200 case...

I sold Apollo 1260 (with 060) with fan on CPU.
Please look this thread:
http://www.amibay.com/showthread.php?t=4986
Before dispatch I installed small (really small) 20mmx20mmx10mm 12V Sunon branded fan on CPU.
The trick is to install the fan just on the edge of CPU if you have CPU socket. And of course you have to add thin spacers between CPU and fan to ensure air flow.
There is no room for any metal heatsink over CPU; forget it.
But 040 and 060 ceramic package has very good heat conductivity, so metal heatsink is not really necessary.

Unfortunately I didn't take the photo with fan installed, but please ask PUMA to send you the photo how the card looks like.
The card with this small fan will fits into desktop, but fan is very close to keyboard anyway.

So please look for 20mmx20mmx10mm 12V fan.

[8bitbubsy]

Thanks for the info, stachu
I think I have a fan like that laying (from an old laptop), but I'm not sure at all on how to mount it on the CPU.. What should I do to make it stick? Hot gun glue? :S

[stachu100]

I added thin spacers (about 1,5mm or 2mm; don't remember) between CPU and fan.
Something like this:
This is Blizzard PPC on the picture, but principle is the same.
You have to add 4 spacers between fan and CPU.
Ad I used some kind of "Super Glue" liquid glue.

As said the best way is to ask PUMA for pictures.

[Allen1]

Originally Posted by dabone

Here's what I did for my 040/40mhz.

http://www.amibay.com/showthread.php?t=4986

Works quite well. I haven't been using it latley, but it ran for hours running games and demos with the bottom cover on with this solution.


Later,
dabone

I don't have an accelerator but if I did, I would definitely be using your second version to keep it cool. There are many duff video cards sold for spares on fleabay where the fan and heatsink assembly work, so this is a very practical idea that is easy to achieve after seeing it done as in your post. Did you use thermal paste between the heatsink and CPU, it looks like you may have but it doesn't say.

It's a shame that something like a northbridge heatsink and fan couldn't be directly used like that on an ABIT NF7 motherboard but these are about 15mm deep and require some means of keeping them locked in place. The same assembly could maybe be used as the fan part of your method though by bending out the fins to direct the air flow when fitted in a casing method like yours.

[rkauer]

Old Northbridge from early k6-2/Pentium2 era are low profile enough to be used over the 040. This and a lateral ducted fan (or a very near vertical fan) will be enough for the accelerator to run at nominal speed.

[Zetr0]

@bubsy

take some time with these links

Anemos ingenius heat-pipe-ducting method and TheoryBoy's inspired take on Heat-Pipe technology - this will probably what you are looking for to be honest.