I am trying to get the Tiny Video Player to go into "Update" Mode.

I held the upper left hand button down while sliding the Power Switch on and it goes into TinyScreen Boot Loaded but when I try and update, nothing is happening.

Can someone please help?

Thanks in advance.

I ran into the same issue with my Tiny Video Player a while back.
In my case, I had to make sure the USB cable was a data cable (not just charging) and that I was using the latest TinyScreen firmware update tool. Once connected, the boot loader screen stayed on, and the update started immediately after selecting the correct COM port.
You might also try holding the button until after the power switch is fully on – sometimes timing makes a difference.

I've had the same issue with the Tiny Video Player! When I tried to go into "Update" mode, it would just stay stuck on the boot screen. What worked for me was making sure the update file was on the root of the SD card and double-checking that the file format was correct before trying again.