Just a month-and-a-half after NVIDIA had to recall most of the SHIELD Tablets it sold up to that point due to a potential fire hazard, the company has to go the same route for the 500GB version of its SHIELD Android TV. Fortunately, this recall has nothing to do with any potential safety hazard.
Through a forum post at GeForce.com, NVIDIA customer service rep ManuelG notes that some users that update to the new 1.4 firmware might experience an issue after a reboot. The most obvious result would be being entered into Android's fastboot screen, which is generally used for low-level maintenance (eg: recovering a stock ROM). It's noted that so far, no reports of this issue have related to the 16GB model.
While it sounds like this is more of a software issue, NVIDIA notes that in actuality, this relates to the hard drive's performance worsening over time. How, we're not quite sure. If you see the fastboot screen after upgrading, you'll need to RMA the entire device - even if you somehow recover from it, as it could reoccur again. You should also RMA the device if you see persistent pixelation in the top row of tiles.
While it's undoubtedly a pain to have to RMA anything, NVIDIA's working to make this as seamless as possible. If you have an affected device (NVIDIA says that will be ~1% of owners), you can submit an RMA request and be sent a replacement as soon as it's approved. Once you receive the new device, you can ship the old one back. If you're outside of the US, getting an immediate replacement might be a little challenging, but NVIDIA says it will rectify things as quickly as it can.
Meanwhile, if you're not sure of what the SHIELD Android TV brings to the table, your next stop should be Marco's in-depth evaluation.