Gentlepersons:
I have a 715/75 workstation.  I have acquired a set of Debian CDs from an official source.
Just recently, but now without fail, the w/s won't boot.  The LEDs display the following messages:

within 2 seconds: 7-5-4-3-2-1

2 seconds later: 6-1

No messages on the monitor on any of the virtual consoles

Any advice as to which FRU is malfunctioning.
any advice or redirection of this inquiry is appreciated

jack dunn