Re: TWGS frustration!

[dalloff@freenet.columbus.oh.us (Dave Althoff)]

RUBYWAND (rubywand@aol.com) wrote:
(quoting me...)
: >.... For now, I am TWGS-less, but I think the solution might be
: >to find the hot spot on the TWGS card and add an 80n86-style CPU fan to
: the
: >card. ....

(then responding)
:      That your System Saver IIgs does not deliver sufficient air flow to
: prevent a thermal failure on the TWGS is not a good sign. The situation
: may be that an IC that normally runs hot was, at one time, allowed to run
: too hot and is damaged. The damage causes it to run even hotter and/or
: makes the IC more susceptible to heat failure. 

Hmmm...Well, my machine DOES have a Vulcan in it, and the fan in the
System Saver is well positioned to ventilate the HD/power supply, but I
question how much circulation it can provide around the middle of the
machine, where the Video Overlay Card, the TWGS, and the Vulcan controller
(soon to be an Apple HS SCSI card...yup, another long, hot card...), not
to mention the CV Tech 4Mb card on the opposite side.  I could certainly
understand if part of the system is overheating even though the System
Saver output air is cool.

:      Finding the hot spot is a good idea. Cooling via an attached mini-fan
: may help, for  a while. Most likely you will end up replacing the IC.

:      By the way, is your TWGS modified for higher speed? Is it powered
: above 5V?

As far as I know, it is a "stock" 8k card.  Here's what I can tell by
looking at it (since it is out of the system right now...)--
28.000 MHz clock crystal
CPU = WDC W65C816PL-OI8922B
Daughterboard socketed chip = "TWGS1.5 8S"
Other labelled IC's are:
   TWGS1A.I
   TWGS2B.I
   TWGS3E.B   TWGS6A.I
   TWGS4B.I   TWGS7A.I
   TWGS5A.I   TWGS8B.I

There is a jumper wire running from TWGS1A.I -> TWGS8B.I, but it is under
the sockets so I suspect that Applied Engineering put it there.

Thanks for all the help and advice!

--Dave Althoff, ][.
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