I was using my watch for one day with poor battery performance,

I was using my watch for one day with poor battery performance, therfore I turned on airplane mode in the watch but on the next day watch died showing aprox 40% of the battery left in it. I connected watch to the charger and it started to shown minimum charge and keep restarting, I left it hoping that it is maybe normal and watch will recharge, but after aprox 2 hours when I came back to the watch I was unabe to turn it back on again, also screen is blank. - I have tried another docking station from friend that have same watch but it didnt worked, I tested my docking station on his watch and it works. - I have disconnected the battery in the watch (small black pin with black and red cable) for 48 hours but it didnt helped - I contacted No1 on facebook and they recommended upgrading of the firmware, but when I am connecting watch to PC it keeps restaring the connection with message on windows 10: USB device not recognize The last USB device connected to this computer malfunctioned and Windows does not recognise it. - I have connected my friend watch and we upgraded firmare without any problems therefore I know that I have installed USB driver correctley. I am completley out of ideas how to sort it, my watch doesnt charge and when connected to PC keep restarting connection, does anyone know what else I can try?

I have had exactly the same problem and had tried all the solutions you named and more. The only thing that worked was RMA the watch. Now I have a new watch (k8-mini) and its working fine. I bought mine in China and RMA took 5-6 weeks, mainly by slow Chinese post

To flash the firmware on the device it must be powered off. Have you looked at the firmware upgrade section?

It turns on when i connect it to a PC, how i can keep it off ?

disconnect the battery for a while and then reconnect - be careful, just carefully lift the power cable plug gently away from the watch main board. Leave it for 30 seconds and then reconnect. This has worked for quite a few people with similar issues.

OK I misread your post, I thought you couldn’t turn it on again, then probably it’s the firmware.
On Windows 10 be sure to install the MTK driver correctly:

if battery are disconnected watch are not connected to PC
But if i reconnect it, watch turns on when put on dock @Pablo_Eleven_Pablo11

In your first post you said “I was unabe to turn it back on again” in your second “It turns on when i connect it to a PC”
Now what is it?
If you mean the watch-screen stays off when you connect it to pc but usb go’s beeping on and of
then the watch seems to be broken as I wrote in my first post.

I have the same problem as in the video, adding the device to the computer continues to restart, so the computer can not find it.

Ok that’s different from my watch which not turned the screen on when connecting to pc.
If you sure the MTK drivers are installed correctly (look in device manager, check in the menu if hidden devices are enabled, you should see “MediaTek Preloader USB VCOM Port”)
Then remove watch from pc (watch is off now) start flash_tool on pc, choose the scatter file, and put it on firmwareupgrade.
Then connect the watch to pc and immediately after click the green download button in flash-tool. and wait if it starts.
Ik it will not start, disconnect watch (its off again, atherewise disconnect battery for little while and connect it again), start flash-tool choose scatterfile and set on firmware upgrade, click on the green download button and immediately after it connect the watch and wait if flash-tool starts.

I’m using Windows 10, does you’re description will be useful on this OS?

Yes, I’m using it this way on Windows 10.
Be sure on the mediatek driver, this is an unsigned driver and will not properly install on default Windows it has to be special installed as unsigned driver.