25 Feb
2014
25 Feb
'14
1:09 a.m.
I picked this link up from Jimmy Maher's article on
the home computer
wars. The article below is from Texas Monthly April 1984, it's a fairly in
depth look at the TI-99 failure.
That was a great read. Thanks for posting
Terry (Tez)
On Tue, Feb 25, 2014 at 1:41 PM, allison <ajp166 at verizon.net> wrote:
On 02/24/2014 05:09 PM, Tony Duell wrote:
>> I noticed the video chip was covered with
a white gunk in a couple of
the
>> units I opened in order to reconstitute
my working one. I understand
this
>> is some kind of substance which aids with
cooling so that chip at least
>> runs very hot.
> White gunk will hurt cooling, not help (white interferes with
> radiational cooling).
>
> I take it you're assuming it is silicone thermal grease. That's
> plausible. But silicone grease only helps cooling if you stick it (in a
> *thin* layer) between the device and a suitable heat sink. The heat
> sink actually does the cooling.
Having several its white silicone based grease
to transfer heat from the
chips
to the the surrounding shield, which is there for EMI/RFI prevention.
Allison
I seem to remember in the TI99/4A that I had
apart there is a metal
screen (shield) around the PCB. A couple of the ICs (I forget which ones)
had silicone grease on them which effectively allowed them to use this
screen as a heatsink. I am not sure it was a very good heatsink, but..
-tony