I just found one of my Roku Streaming Stick devices (it says SKU 3600## on a sticker with barcodes in the box, where ## is a country code). It had been put away for a very long time.
Anyway, I set it up on a TV, and updated it. After the update, I noticed AirPlay showed up in the settings and shortly after Guest Mode was enabled--I had enabled it from my account settings but only after the update I assumed it gained the functionality of remotely setting settings on it.
I failed several times trying to disable Guest Mode directly on the device because I didn't remember the passcode so a set up a new one in the account and disabled Guest Mode for this device, which unlike the rest on the list now it had a status that wasn't years old.
So far so good. Then, when the Roku device received the new settings it started doing its thing culminating on a restart, I thought, except it never came back. The device outputs no video and I noticed the LED flashes in white twice every second or so after the power up sequence--or whatever is happening when it's solid white when first power is applied.
I tried it in other HDMI ports, same thing. I went from TV to TV all HDMI ports on the TVs and AV receivers, always no signal, constant 2x white LED flash. To be clearer; the blinking is not random at all, it appears timed, like and indication of something. (longoff-white-white)
The device had been in storage and I know it should be working, I just witnessed it. Thanks to the account page I know for certain when the device was purchased and, though it's been a while I have Apple TV boxes bought on the same year that are still working--these took whatever workload Roku might've had at the very least saving it from heat damage from normal operation...not that it should be a concern, anyway. It makes no sense for it to brick itself, literally just taking it out of the box and used as instructed. It wasn't used more than a month, maybe month and a half when first purchased either--it still has the new plastic smell.
I've like a million questions, but the must-know-first is/are: what does the blinking mean? How can I restore the device to a working condition? Does this happen often? Is this intentional by Roku to push users into new hardware? I hope it was a really bad coincidence because I actually want to get a few more if not true, I like the headphones-in-remote feature.
Roku has never told us what the blinking lights mean or if there's different sequences, but it most likely means it's not connected to your Wi-Fi. There's a reset button on one of the edges. With everything connected press and hold that button for no less than 30 seconds.