To troubleshoot the issue with your Sumi device not working after two uses, follow these step-by-step instructions:

1. Power Cycle the Device:
- Press and hold the power button for 2-3 seconds to power off the device.
- Wait for about 10 seconds and then press the power button again to turn it back on. This can reset minor software glitches - learn more.

2. Check for Software Updates:
- Ensure your device's operating system is up to date. Navigate to the settings and look for system updates that may need to be installed. Outdated software can lead to operational issues - learn more.

3. Verify Google Mobile Services (GMS) Installation:
- If the device requires GMS and it isn't installed, the application may not function correctly. Make sure GMS is present on your device; if not, consider reinstalling it - learn more.

4. Inspect Hardware Connections:
- Check all physical connections, including chargers and cables. Faulty connections can prevent the device from functioning correctly. Ensure there are no visible damages - learn more.

5. Reset the Device to Factory Settings:
- If the above steps do not resolve the issue, you may want to reset the device to factory settings. However, be cautious as this will erase all data on the device. The resetting process can usually be found in the settings menu of your device - learn more.

6. Seek Remote Assistance:
- If the problem persists, consider utilizing remote assistance from Sumi's technical support. They can help diagnose and potentially fix the problem remotely - learn more.

By following these steps, you should be able to identify and possibly resolve the functionality issue with your Sumi device. If the problem continues, it may require more in-depth assistance from customer support.