Re: More ZipGS Upgrade Woes!!

["Marvin Miller" <marvinmiller@hotmail.com>]

Ed, Thanks for the reply...

It's really this simple - with the old -7 processor all is well. When I
install the -14 and re-boot the screen comes up garbled. If I re-boot enough
times I will see the proper screen where it says Rom 3 etc but that's it. It
will stop dead.

I checked the pins on the chip and they all looked straight etc. The
socket's pins are within their little slots. The chip was  installed the
right way. I contacted the company that helped me out by selling me the
single chip (a big favor!) and they are game to replace it but they are
asking me technical questions which I cannot hope to answer such as;

What logic level do you measure on the Reset pin.  We don't know your
circuit, but is the reset circuit stand-alone or does its actions get
modified by a signal
which in turn depends on the the MCU operation (watchdig function). So if
the reset line is holding the MCU in a reset state, try to determine why the
reset is clamping the MCU from running. Then try to free the reset clamp and
see what
happens. Doing this work will give additional insight, which may be helpful
just in case the new MCU also does not want to run.  Please note that I am
open
to the idea that the MCU could be DOA or suffered some static damage
during handling somewhere along the long chain of people.

To me it's as simple as this;

The old -7 Chip works well. The new -14 does not work. I can try removing &
replacing both until the cows come home. The -7 will work, the -14 will not.
The chip part numbers are identical except for the speed designation...

Arghhhhh....

Marvin



<noone@nowhere.net> wrote in message 3A76E8B3.3C4CE2C2@nowhere.net">news:3A76E8B3.3C4CE2C2@nowhere.net...
> Marvin:
> Well if the CPU is all you have changed, and the problem is not
> consistant, I'll go with a bad connection somewhere.  I'd check the pins
> on the 40 pin header that plugs into the motherboard CPU socket. I ended
> up losing a corner pin and had to build a new cable.  Of course if you
> handled the CPU chip, I'd suggest cleaning it with Everclear, and the
> CPU socket as well.
>
> Here's a little tip for those putting an accelerator in and out of your
> IIgs while experimenting.  Remove the cabe from the card and leave the
> cable attached to the CPU socket.  This is the weakest link and has
> caused me lots of headaches.  I have heard this from others in the Apple
> community that this is often the problem.  However, since I started to
> leave the wire on the motherboard, I have not had nearly as many
> problems with intermittant connections.
>
> Thankx,
> Ed
> eeastmanNO@SPAMapple2.com
>
> Marvin Miller wrote:
> > Hi Friends; I got a new WDC processor for my ZipGS and am having
problems with it. I suspect it's DOA but could use some more opinions...