photos:The Onyx FDDI mezz problem

The Onyx FDDI mezz problem

When I got the Onyx, it had an IO4 SCSI mezz in the lower position on the IO4 and the top position was free. I installed a dual DAS FDDI mezz in the top position, only to find out that the cardcage locking bars covered the top FDDI connector (the locking bar would still install, though).

I proceeded to swap the SCSI mezz and the FDDI mezz around. This is the assignment in the pictures here. This makes the problem worse: both locking bars don't even fit anymore, as is obvious (hopefully) from the pictures. The mezz assignment as seen here clearly doesn't work and I'll have to go back to my original setup. This leaves the top FDDI connector covered unless I modify the locking bar.

1/3/07 Update

Well, it seems I wasn't crazy after all. According to this site: http://www.gisparks.tas.gov.au/sgi/OnyxRealityEngine2.html: 
Some points to note are:

# The MC3 and the IP19 board ends are covered with a perspex sheet. As I
understand it this is essential for proper cooling of the CPUs, SIMMs and
other boards. Despite this, some MEZZ boards (eg. FDDI) have installation
instructions which tell you to remove and discard the locking bars and
perspex sheet! I didnt do this - I just bent the offending tab on the bottom
locking bar up so that it didnt interfere with the FDDI MEZZ board.
Cardcage
SCSI mezz in top pos, FDDI mezz bottom, VME1 free, VME2 = VFE, VME3 = ATMDate: 2007:03:01 00:09:10 		Closeup of bottom.
Note how lowest FDDI connector is below the leavers on the boards, and how VME1 is open (and how close it is to the IO4 mezz!Date: 2007:03:01 00:07:27 		Closeup of top
SCSI connector (DF SCSI 1) is quite high on the board, but the FDDI mezz has them even higher.Date: 2007:03:01 00:13:00 		Slot assignment.
How the slits in the cardcage locking bars match to the slotsDate: 2007:03:01 00:08:25
Part number
013-0578-003 rev A / 040-0470-001 rev DDate: 2007:03:01 00:08:40 		Bottom locking bar
Doesn't install because lowest connector on FDDI mezz interferes with it.Date: 2007:03:01 00:11:34 		Top locking bar
Doesn't install because SCSI connector is in the way.Date: 2007:03:01 00:14:34 		Locking bars and transparent cover
To guide airflow over MC3 and IP25Date: 2007:03:01 00:17:30
Cardcage again
Date: 2007:03:15 20:02:45 		VFE board
Date: 2007:03:15 20:04:22 		VFE Closeup
JumpersDate: 2007:03:15 20:05:03
Created with the tool album tool from David's Marginal Hacks on Sat Jan 8 20:54:03 2011