am not sure if you are still in support (possibly not, though if you are i would raise a ticket for the support team)
for the current issue though, can you see any lights on the drobo for power (and also on the psu brick) to see if they are showing or flashing any colours too?
(am not sure if the gen2 psu is fully compatible though there is a page here with some more info in case you are able to try with another compatible psu just in case)
and some more info here in case there is a red light it could be overheating too?
can dashboard still recognise the drobo? if that can no longer see it, then it could be that the main unit has a problem (though is worth trying another psu as well, just in case the gen2 psu doesnt have enough power for it)
if it is just the hardware, and if the diskpack is ok, then the best way to get access to the data again could be to try the migration process, with a replacement compatible model, for example as mentioned here:
(when my drobo-s-gen2 had a faulty power switch, i was able to successfully migrate my diskpack and access all data again.)