If your Chromebit is continually falling asleep/going to a “NO SIGNAL” screen, it is likely that your power management option isn’t set correctly. To set up power management:
Open the Settings Menu
In the lower right corner of your screen, click the time. A box will appear. If you can’t see the time due to issues with your screen size/resolution, hold down Alt + Shift + S on your keyboard to pop it up.
Click the gear icon in the row across the top:
Now on the left, scroll down and click on Device and then Power:
You will see the power management options here, and it will ask you what you want to do when the device is idle. Choose “keep display on.”
Close out of the Settings window and return to the desktop.
You may now open a fresh Chrome window and re-enter the URL of your board to bring it back up if needed.
+++ If you do NOT see "Power" as an option under Device, you might need to update your Chromebit. The final update for Chromebit was 86.0.4240.199. If you are on a lower number than that, in the column on the left, scroll all the way down to "About Chrome OS" to click and check for updates. It may take multiple update cycles to fully get to where you need to be, so it's fine if you have to come back more than once. When done, reboot your Chromebit and do the power management steps from the beginning.