See links below for Quorum's Discontinued Product Operating Manuals and Circuit Diagrams
manuals etc:
http://tinyurl.com/qcvfwcu
Discontinued Product ID (the names may have changed e.g. ISI PS-2 = E5000):
http://tinyurl.com/petcho5
As a DIY'er, in the spirit of 'praise where praise' is due, I applaud this level of customer service.
Gareth