It’s a little noisy, but when I plug my 5N2 in the fan fires up. which is great… Happy that the drives are being kept cool. Except they’re not going to get warm because they’re not spinning up - nothing other than the fan seems to power on - the power switch doesn’t seem to do anything…
Sorry to hear about your problematic Drobo.
My recommendation would be to first try to recover your data, if you have no other backup. To do so, you’d need to find another Drobo 5N2 (I think another recent 5-bay Drobo might also work) to put your disk pack into so you can hopefully access your data there and back it up to another location.
Now, onto your Drobo problem. If your Drobo is new enough, it might still be under warranty. You can contact Drobo support to see if they can help you. If you’re out of warranty, you may want to think about buying Drobo Care to get service.
If you want to troubleshoot it yourself, you can put in some new drives and see if you get different results. You also mentioned that the power switch doesn’t seem to do anything. You might have a faulty power brick, though it sounds like some power delivery mechanism is broken internally. If you’re feeling brave, you can try to take apart your Drobo (there are some videos online) to see if anything is loose inside, or if you notice anything else amiss.
Maybe some other forum members might have some ideas.