So I've had the same problem. Updated the firmware and now the unit is bricked. Red light flashed. I formatted a USB stick but I'm not sure how to install it? Just turn it on and hope for the best? I tried that and notice no difference.
Can anyone help? Do you hit reset button? Is there a factory reset setting?
Inside the download you will find imageUSB.exe and z1_static_100_09_14.7z files.
Extract the .7z file and you get an .img file.
Use the imageUSB.exe to burn the .img file to a USB stick.
That's all.