Unable to Secure a Printer with Sentry due to Certificate Issues

  • Published on Jun 22, 2025
  • 1 minute(s) read
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Problem

The MFP could not secure to the Pharos MFP Site Service due to:

  • An HTTP 503 error when attempting to contact https://NameOfTheServer:4321
  • A TLS handshake failure caused by an invalid or untrusted SSL certificate

Resolution

Following steps can be taken in order to resolve this issue:

  1. Clean and Reinstall Pharos Services (only if none of the Sentry MFPs are working)
    Fully remove previous Pharos Device Scout and MFP Site Service installations.
    Reinstall using the official provisioning package from the Pharos Cloud tenant (Device Scout download).
  2. Generate a Correct Self-Signed SSL Certificate
    Create a certificate with the correct CN: NameOfTheServer.
    Ensure the certificate is placed in the LocalMachine\My store.
  3. Bind the Certificate to HTTPS Port 4321.
    Use netsh http add sslcert to properly bind the new certificate to 0.0.0.0:4321.
  4. Verified the Service Endpoint.
    Confirme https://NameOfTheServer:4321/Mps.Client.Mfp/MfpDeployment/MfpDeployment.svc is accessible and returns a valid response.
  5. Install Certificate on the MFP.
    Export the certificate to .cer format.
    Upload it to the Toshiba device to establish trust.
  6. With these steps, the MFP printer should successfully secure against the Pharos MFP Site Service.
  7. TLS communication should succeed, and MfpDeployment.svc should respond as expected

Should the issue persist, please reach out to Pharos Support and we'll investigate this further.