The power supply for a Gen 3 died a few months ago and they’ve been Out of Stock forever. In the interim that Drobo has been inaccessible, so after inquiring here I decided to try a 5C PS. They were also OOS for a long time. Finally, B&H had the 5C PS in stock at $80!
The original PS had no power light. That was a shame as it would have sped up troubleshooting a non responsive G3 significantly.
The DC Out cable had a straight coax plug which was easy to grasp and plug in, especially when dealing with a Drobo in a space where reach is awkward at best, without removing it to plug in the PS.
One step forward, two steps back.
The 5C PS has green LED to show it has AC power, a welcome improvement. It’s also rated 12V@10A vs the G3’s 12@ 7A. More current handling for more, bigger drives than the G3 might see.
The 5C units have a right-angle coax (aka barrel) connector instead of the former straight version, with plenty of room on the 5C to accommodate the new angle. This, combined with the RF choke located closely to the connector allow for only one angle to connect to a G3. That angle not only blocks most of the access to the Power button but also tends to pop the coax connector out of the PS jack/port. You don’t want that. Nobody wants that.
So my solution was to use a duct tape strain relief holding the 12V cable in place. Inelegant but it works well. In fairness I am using a PS not designed for the G3. The G3 is no longer for sale so Drobo won’t be upgrading its PS. It’s either get a 5C etc., PS or source a generic but suitable one especially if you’re using larger drives.
So a 5C PS will work in a G3 Drobo, it’s just a little awkward. If you’re of a mind to find something in the wild, the coax connector has an OD of 6.6mm and an ID of approximately 3mm. There are several standard combinations of inner and outer diameters so you need to be sure of the sizes before spending a lot of money.
12V@7A is probably fine for 4 x 4T but if you go larger, 10A is a better choice. PSs don’t “push” Amps, they allow devices loads to “draw” them as needed from the PS, as long as it can provide sufficient current for the load.