imageCLASS MF634Cdw scans legal size, but not letter

[kurema8]

Recently, my #MF634Cdw can't scan documents using the Canon MF Scan Utility unless the Paper Size is set to legal, despite my attempts to scan letter-size documents.

MFSU throws off a variety of error messages, including:

Cannot communicate with the scanner.
The cable may be disconnected, or the scanner may be turned off.
Check the scanner status and try again.
Scanner driver will be terminated.
Error code: 600104

and

Cannot communicate with the scanner.
The cable may be disconnected, or the scanner may be turned off.
Check the scanner status and try again.
Scanner driver will be terminated.
Error code: 600108

Switching to Paper Size Legal works fine, but there is excess space on the PDF, which is sub-optimal.

I'm using a MacMini M2 Pro running Sonoma 14.5. and have reinstalled the latest Canon drivers currently on the site.

Any help would be much appreciated!

[kurema8]

[Hector]

Hello, 

That error would point to a connection issue or a problem with the settings in the MF scan utility. We would be happy to assist, but we would need some additional information to assist further. You can reply to this message with the information below and we can provide some troubleshooting steps or suggestions. For a more immediate resolution I would suggest contacting support over the phone at 1-800-652-2666. Our agents would be happy to assist.

1.What version of the Mac or Windows operating system are you using on your computer?

2. Are you connecting via USB or is it over a network?