Drobo powers off after 30 seconds

Drobo powers on for a about 20 to 30 seconds and then powers off. The power light at the back of the unit is flashing the whole time. On the front of the unit all the lights come on, then the capacity lights go off, the drive lights are yellow whilst the unit is powering up, a few seconds later the whole unit powers off. The power light on the PSU is also on the whole time. I have removed all of the drives as well and get the same result. From reading similar posts here I suspect the PSU may be the issue.

Model: Drobo 5N

Any ideas.[hr]
I have checked all connections and the unit hasn’t been moved or relocated recently.

hi it might be the psu, in which case trying to get another one could fix the problem, but can i check if any power lights were showing red? (that could be overheating)[hr]
here is also a page with some more info about psus: