The vendor generously offered a refund and let me keep it to repair or dipose of.
I then bought what I thought was another Chase IOLAN RACK+, but it fact it was the non-rack DB25 version with external PSU.
I decided they probably had the same voltages, so I could swap the PSU around, and with a bit of metal bending get things working for the RACK model.
While prodding the RACK+ PSU with my voltmeter to work out how to splice in the new PSU it suddenly started working; I guess the problem is most likely dry joints.
Next I find that my RJ45-DB9 cisco console cables don’t work. I find the Cisco pinout at http://www.technick.net/public/code/cp_dpage.php?aiocp_dp=pincabser_cisco_9 and by conferring with the Chase manual, come up with this colour mapping.
|IOLAN||CISCO||RJ45 Names||RJ45||DB9||DB9 Names|
I cut off the RJ45 from the Cisco cables and make my own, which work fine!
So, as I crimp on a new RJ45, my colour mapping is:
NONE, BLACK, BLUE RED GREEN ORANGE WHITE BROWN
with yellow dangling/
Hurrah! I can now control 16 devices at once using debian’s cylcades-serial-client; all much more satisfactory that USB com ports which have given me no end of trouble.