OK, so some strange goings on. I was watching a movie on my MacBook (details in my profile) and had it connected via an HDMI cable to a SHARP TV (4T-C70BK2UD), and the battery backup battery side must have gone out, because suddenly it made a loud, constant, high-pitched sound, and light was blinking red and green. I force shut down the battery backup (APC 350) by holding down the power button, but didn’t think to turn off the TV or computer.

After turning it back on, the shrill sound resumed, so I tried another time, and ended up moving the TV power cable to the power strip side, where everything else was. That stopped the sound (I guess I just need to get a new battery for it). I could use all the devices, but the TV could no longer find my laptop through the HDMI cable. I tried restarting the TV and checking all the inputs. I unplugged the HDMI for my computer and also restarted my computer because it was acting all glitchy with the screen flickering around, and especially after looking at “displays“ in settings, it seemed clear that it was trying to find the TV but couldn’t hold a connection.

After restarting the computer, it behaves more normally, but still was having trouble securing a connection to the TV, and the TV could not detect the computer. Finally I tried a different HDMI, and then I was able to connect. Is it possible that having the TV abruptly turned off through shutting off the battery backup messed up the HDMI cable? Can that kind of thing happen?

But there’s more. Normally when the TV is turned on it goes to the Firestick immediately. This time it was not doing that. I went to the Firestick manually, and it could no longer give me the home screen, citing connectivity issues, but I think that’s because I’m having Wi-Fi issues and have to have it reset. I re-entered the password for the Wi-Fi and it still was not bringing up the user account, and then suddenly it woke up and everything seemed OK, until I noticed it was on a different user on the account, and for some reason the primary user had vanished into thin air! What happened to it? Where did it go? Did I somehow mess up the TV?