USB ports fried on two Drobo's?

I have two Drobo’s - a first generation (USB only) and a second generation (USB/FW), both four-drive units. Both have been connected to a Time Capsule through a USB hub, and have been working fine for quite a while. Recently both drives went offline simultaneously. I connected both to a Mac for direct testing. The current status is:

-1st Gen Drobo: Looks to start up ok (normal light sequence), then goes into sleep mode. Dashboard doesn’t see the drive at all. Neither does System Profiler or Disk Utility.

-2nd Gen Drobo: Does the same as the 1st Gen when using USB, but if I use Firewire it works fine.

I’ve tried multiple USB cables and ports, plus verified the Mac saw other USB devices on those ports and cables fine.

Q1: What the #$*@? Has anyone seen this happen, where multiple Drobo’s lose their USB ports simultaneously? The USB hub is still fine (although I’m bypassing it for this testing). Any thoughts on troubleshooting further?

Q2: If I move the four drives from the Gen1 to the Gen2, will I still have access to the data? I’d like to pull everything off the Gen1 if at all possible.

Q3: Any idea what repair costs might be, if worthwhile?


  1. its possible that he hub fried them i guess, but ive never heard of it

  2. yes - but you might not be able to go back to the gen 1 once the pack has been upgraded

  3. no idea im afriad

Thanks. It’s conceivable the USB hub somehow fried the ports - but I’ve also never heard of it. Everything is on a surge protector which plugs into a UPS. The USB hub itself is still fine, as is the Time Capsule (the only other device on the hub).

As long as I get the data offloaded I’m fine if the drives no longer work in the 1st gen Drobo. After all, a 1st gen Drobo isn’t terribly useful without a working USB port. If I get it fixed I can reformat the drives. Right now I’m backing up the data from the 2nd gen, then I’ll move the drives around.

Thanks again.

I had a powered USB hub fry my MS wireless keyboard transceiver.

The iMac was plugged into a UPS, but the USB hub was directly into the wall.

It was a Belkin, not an ‘off brand’. Anything can happen. I would suspect your USB hub.

Ground differences are evil things. Always plug all connected equipment into the same-grounded outlet (surge protector or UPS) if at all possible.

What version of OS X are you using? Currently 10.6.5 has USB connection issues for all USB devices.

You can move the drive pack from a Gen 1 Drobo to a Gen 2 Drobo. The only difference between the two devices is the Firewire connectors on the back.

Thanks everyone for discussion and suggestions. I’m working (slowly) with Drobo tech support. I suspect I’ll be moving the drive packs over tomorrow.

I hadn’t read about the 10.6.5 USB problems. Good to know - the Mac I’m using for the diagnostics is indeed 10.6.5. I was curious, so connected an old MacBook running 10.4.11 to both units via USB. Neither unit was recognized - neither Drobo Dashboard nor System Profiler saw it. So this particular issue doesn’t appear to be related to 10.6.5.

All devices were connected rather cleanly. They’re in an equipment rack with typical office network gear. All devices go into a power distributor (rack-mounted power strip), which in turn is plugged into a rack-mounted UPS, which in turn is connected to a decent surge protector, which in turn is connected to a dedicated circuit.