If your SERIES-B Tilt is refusing to do anything at all and the screen is staying blank, the first thing to check is whether it's turned off. Clicking the main button five times quickly will turn it off, so clicking the button another five times quickly should get it working again.
Also, check to see if the IMR 18650 battery is loose. If so, it could be that a solid connection is not being made with the battery and so the device has no power. You can then gently raise the negative battery connection with a small screwdriver or tweezers and this should create a solid connection again. To lower the chances of this happening, please see the below video to ensure that you're removing the IMR battery safely.
If an error message is displayed when you try to use the device, please check this article for an explanation of these messages and how to solve them.
If you need any further help after trying these troubleshooting tips, please get in touch!