To resolve the "No connection to server" issue in TeleGuard, follow these step-by-step instructions:

1. Check Network Connection:
- Ensure that your device has a stable internet connection. Test this by trying to open a webpage or using another internet-dependent app.

2. Restart Application:
- Close the TeleGuard app completely and restart it. This action can refresh the connection to the server.

3. Update the App:
- Make sure that you are using the latest version of TeleGuard. Go to the Google Play Store, search for TeleGuard, and check if an update is available. Update if necessary.

4. Restart Your Device:
- Restart your device to refresh all network settings and app functionalities.

5. Check Server Status:
- Sometimes servers may be down for maintenance. You can check the TeleGuard's status on their official website or community forums to see if other users are experiencing the same issue - learn more - learn more.

6. Clear App Cache and Data:
- Go to your device's Settings > Apps > TeleGuard. Click on Storage, then tap Clear Cache and Clear Data. This step will reset the app’s settings.

7. Check Permissions:
- Ensure that TeleGuard has all the necessary permissions to access the internet. Go to Settings > Apps > TeleGuard > Permissions and confirm that permissions for data usage and network access are enabled.

8. Reinstall the App:
- If the issue persists, uninstall the TeleGuard app and then reinstall it from the Google Play Store. This will ensure you have a fresh installation - learn more.

9. Contact Support:
- If none of the above steps work, reach out to TeleGuard's support for assistance. User support is integrated into the app for easier access - learn more.

Following these steps should help you resolve the connectivity issue with the TeleGuard server. If challenges persist, keep an eye on community forums for updates regarding known outages or issues affecting the service.