Re: ZipGS 15/64 problem was heat related!

[spec@vax2.concordia.ca (Mitchell Spector)]

In article wily@svpal.svpal.org (Paul Creager) writes...

>Mitchell Spector (spec@vax2.concordia.ca) wrote:
>:     By removing the lid and running a fan over my cards, everything
>: runs 100% stable and oddities disappear.
>
>Mitch, here you have changed _2_ things, you removed the lid (#1) and you
>tried the fan (#2).  Let's employ the scientific method.  Have you tried it
>without the lid and no fan?  The reason I ask is because I've heard that,
>in some rare instances, the metal RF shielding in the lid reflects the
>right frequency of noise to affect the Zip.

    Yes, removing the lid does absolutely nothing. It is not until I
point the fan at my cards that things run stable. If I switch off the
fan, things continue to work smoothly for, oh, around 30-60 seconds.
Then of course the locks-ups and oddities immediately begin again once
the cooling is gone. Switch the fan back and like magic, in a few short
seconds everything is fine.

>As for the cooling, the ASIC is culprit.  I've been tempted to try one of
>those cooling devices myself.  Let us know if you try it, and if it
>blocks the adjacent slot.

    I should take back what I said earlier about all chips being
"cool to the touch". I felt them again, this time comparing with
the DIP 65C816 on the Zip (which isn't connected) and some of
them feel slightly warm. The ASIC seems most notiably so...

    The question is, where would I mount an internal fan so it
blows on the ZipGS board (or better yet, on the ASIC directly).
I had a peek inside my brother's 586-160 PC, there is a mini
CPU fan with two wires running from it (red and black). The
fan is marked "CPU Cooler, DC 12V, 1W". Perhaps I can purchase
a similar fan place it over the ASIC (or PLCC 65C816?). Using
some twist-tie, I should be able to mount it on the ZipGS card.

    The "fan" connector on the GS motherboard has two pins.
I assume one is 12V and the other ground, so I can probably
just wrap the wire around the two posts. I'm using a stock
60W Apple supply though, so I'd be somewhat concerned about
overloading it.

Mitchell Spector
spec@vax2.concordia.ca