Thank you Perderabo!
I was loosing the hope of someone replying to my thread!
Yes, I did find those articles as well some basic information about these servers at
http://www.openpa.net/index.html .
Are you sure the pdf documentation of these servers was available ? and where at docs.hp.com? I was told that the documentation was never released in the pdf or html format because these servers were released sometime in 1991 and there was no acrobat reader or html docs that time and one can only find the hard copies.
Anyway, the information I am looking for is their service manual. Info like lights indication/codes , how to read the event/error log etc.