It sounds like you're dealing with a specific network or authentication issue on the problematic machines. Here are some steps you can take to troubleshoot and potentially resolve the issue:
Check User Authentication Settings on the Printer: Since the printer works when logged in as an admin but not for other users, ensure that the user authentication settings on the Konica Minolta C454 are configured correctly. Go to the printer's web interface (from another machine that can access it) and verify that user credentials and access permissions are properly set up.
Review Printer Driver Configuration: Make sure the printer driver on the affected PCs is the correct version and configured properly. Sometimes, using the wrong driver version can cause authentication failures. Ensure you're using the specific driver provided by Konica Minolta for the C454 and that it's updated.
Network Configuration and Connectivity: The fact that you can't access the web interface of the problematic copier from these machines suggests a network issue. Check the network settings on both the PC and the printer. Ensure the printer is on the correct VLAN or network segment and that there are no IP address conflicts. Test connectivity by pinging the printer's IP address from the affected machines.
Check for Network Policies or Restrictions: If there are network policies, such as those set by group policies or firewalls on the school's network, they may be blocking access to the copier's IP address or port. Ensure no restrictions are preventing communication between the PC and the printer.
Reset Printer and Network Settings: If possible, reset the printer's network settings and reconfigure them. Sometimes a fresh configuration can resolve underlying issues.
Check for DNS or Host File Issues: If the printer's hostname is used instead of the IP address in the printer settings, ensure that DNS is properly resolving the printer's name to the correct IP address. Alternatively, check the host file on the problematic PCs to ensure there are no incorrect entries.
Printer Firmware Update: Check if there's a firmware update available for the Konica Minolta C454. Sometimes, firmware bugs can cause unexpected behavior, and updating to the latest version can resolve these issues.
Test with Another User Profile: Create a new user profile on the problematic PCs and test printing with this new profile. Sometimes, issues with user-specific settings or corrupted profiles can cause printing errors.
Contact Konica Minolta Support: If all else fails, contact Konica Minolta support with detailed information about the issue, including any error codes or messages displayed on the printer or the affected PCs. They may have additional insights or updates for you to apply.
By systematically checking these areas, you should be able to identify the root cause of the problem and take steps to resolve it.