Re: Faulty Apple IIe

[mjmahon@aol.com (Michael J. Mahon)]

Joe Cairnes wrote:

>A few years ago I had what I recall was an identical problem.  I solved 
>it in just the way you suggested you might solve yours.  It took 
>replacing one chip.  I think that that chip was the IOU.  As it happened 
>I did not know which one to replace and replaced two or three before the 
>mahine was right.
>
>Try the IOU chip.  If that does not do it, try others--you'll find the
>right (bad) one. 

It certainly isn't impossible that the IOU chip could fail, but it is
pretty unlikely.  Much more likely is that one or more chips have
developed bad contact with their sockets, and reseating them
(or replacing them) creates enough friction on the pins and sockets
to break through the oxides and permit good contact, thus correct
operation.

For fun, you might want to try putting the original IOU chip back
and see if the machine still works.  It probably does.

-michael

 Email:  mjmahon@aol.com
 Home page:  http://members.aol.com/MJMahon/