Step away from the keyboard, get outside, go somewhere you enjoy that isn't related to work or the computer. I for one feel spending a few days without tech is a good way to clear my head and refocus and get some motivation back. Disconnecting to me has a way of helping me reboot essentially.
When I say disconnecting too, I mean seriously disconnecting. No phone, no social media, no laptop etc. I usually have my phone of course for emergencies etc, but it stays only for phone or emergencies and nothing else.
Usually my motivation loss is related to burnout, so this works really well for me.
Why do you feel burned out? That can help figure out ways to adjust.