Hi,
UPDATE:
I decided to open the core stack of my spare storage module to check
if the open X wires where repairable.
After opening the stack carefully at a plane with two open X wires I found
out that the open spot in the X wires where located at the black 'foam'
which IBM had put in between planes for airflow reasons.
See white arrows in http://home.hccnet.nl/h.j.stegeman/CoreProb3.JPG
The X wires where broken by a chemical reaction between the copper wires
and the black 'foam'. This 'foam' becomes over the years very sticky black
tar. I now also understand why only X wires where open and none of the Y wires.
I also checked the tension/slack in the X/Y wires to see if shrinking (by frost)
could break them. This is not the case.
Conclusion:
It was not the unheated storage of the system (my resposibility)
but the chemical timebomb between the aging 'foam' and the X wires
that caused the defect in all my core modules.
I am now planning for a chip replacement of these core modules.
Henk
