Scott Olswold

Sentry Print: Securing a Device Results in White Screen and "Spinner"

Blog Post created by Scott Olswold on Jul 16, 2019


When securing a device for Sentry Print in Blueprint, the "Status" in Pharos Print Center says "Secured" but the device, on reboot, only has a white screen with an animated "spinner" as if it is still loading.


Causes of the Problem

This problem has several potential causes. Each is described below.

Connectivity to the Server - Name Resolution

When securing the device, the server designated in the dialog box is sent to the device as the host name. If the DNS settings on the device cannot resolve the host name, the Pharos software installed on the printer will not load, causing the visual symptom described above.

Connectivity to the Server - Port Access

The device will attempt to reach its parent server on TCP 4321. If that port is being blocked (firewall software, switch, router, etc.), then the connection cannot complete and the Pharos software installed on the printer will not load, causing the visual symptom described above.

Invalid Device Settings

If the terminal for the device was present on the Analyst server prior to securing the device, there is a possibility that there is a difference between what is expected for the device and what is actually present. At launch, the device-side software requests its configuration information. The server-side software catches this invalid data and quashes the request. Because the configuration is not downloaded, the device software cannot launch, causing the visual symptom described above.



Name Resolution Issues

Use nslookup to determine if the issue is due to failure in name resolution. If used as-is, nslookup will use the host's primary DNS server to resolve the server name. However, the command can accept another DNS server as well, making it a very flexible troubleshooting tool. In the example that follows, "" is the device's parent server and "" is the DNS server defined on the device. So to check name resolution, the command to run is:




If the response includes a "can't find <servername>" statement, then the DNS server does not contain a record for resolution.


Resolution: Either add the necessary record to the DNS server or reconfigure the device for a DNS server that can resolve the name.


TCP Port Access Issues

To determine if it is a port access issue, locate a workstation on the same subnet as the device. Engage a command prompt (it does not need to be administrative) and use telnet to reach the server over TCP 4321. In the example, the server name is Note: you may need to install the telnet client; use "Add Windows Features" to do this.


telnet 4321


If successful, the command prompt window will change to simply be a screen with a flashing cursor. Otherwise, it cannot make a connection.


Resolution: Evaluate the network device path between the device and the server to determine where the 4321 TCP port is not allowed, and then open/white list it.


Invalid Device Settings

This usually happens because an existing Terminal is present for the device in Blueprint prior to attempting to secure the device. As part of the securing process, Sentry Print will create a terminal record that is appropriately configured (use the Secure Release Server default settings to set the Print Group and authentication script for the terminals) for the device.


Resolution: If a terminal was already present when the device was secured:

  1. Unsecure the device.
  2. Launch the Blueprint Administrator application on the Analyst and delete the terminal record.
  3. Within the Analyst's Blueprint Administrator, clear replicated data on the device's parent server.
  4. Resecure the device.