01-09-2020 06:52 PM
My Color imageCLASS MF644Cdw has problems staying connected to a PC. My primary PC is a desktop connected via USB to the printer. It will initially scan or print for some amount of time then connection issues will occur. Sometimes prints will be sent and just sit in the spool.
Occasionally I will be scanning using the MF Scan Utility and after a few documents I will initiate a scan, the scanner will move slightly, then it will stop and the printer will show a status bar for scanning that never goes away. Occasionally, but not always, this is also accompanied by the MF Scan Utility window disappearing. When this occurs I can cancel the can on the printer's screen. I can then initiate a scan from a second computer over WIFI. This will work until the after a few documents or an amount of time and then that other computer has the same issue. All this does occur even when the PC's are staying awake. I also have an issue where after a sleep cycle the scanner will not communicate. This is consistent. I have to restart my PC and sometimes the printer to regain communication.
All my drivers and software are up to the latest dated on the product website. I am running Win10 x64.
01-13-2020 12:06 PM
Hi JeffBradway.
If this was a problem with the printer itself, then the second computer would be unable to scan when the first computer was.
If the problem requires a restart of the computer to correct, double-check that the security software (firewall, antivirus) have been set to allow the MF Scan Utility and the MF644Cdw to communicate unobstructed. Refer to the security software's documentation and support for directions on adding exceptions. This will need to be done for both computers.
If you need immediate assistance with this issue, please contact us using the numbers and information at http://Canon.us/ContactLI
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01-15-2020 09:07 PM
I tried explicitly giving MF Scan Utility direct access through windows firewall for both incoming and outgoing connections. I also excluded the entire MF Scan Utility folder from my virus protection scanning (On-acess and On-demand). The result is the same. Occationally I can start a scan and I hear the scanner check the platen (even though there was previously loaded a sheet in the ADF) and then the printer screen shows Scanning and it hangs there. The MF Scan Utility window closes. After a while the printer's screen beeps and closes the Scanning status. If I then try to initiate a scan from the printer to the computer it tells me to connect the computer.
This recently happened and after I was able to send a print job successfully without any restarting of the PC or printer. I tried launching MF Scan Utility after successfully printing a job and clicked the Document scan. The utility told me:
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.
In Devices and Printers I right clicked the Canon Generic Plus UFR II V120 and hit troubleshoot. The only suggestion was to make the fax the default printer. I then right clicked and chose Scan Properties->Test Scanner I received the following:
Your imaging device successfully completed the diagnostic test.
The scaner is listed as Canon MF642/643/644. Status: Device Ready. On Port: \\.\Usbscan0
I also checked Services.MSC and saw that the Windows Image Acquisition (WIA) service was Running and set to Automatic start.
After performing the diagnostic test above, I started MF Scan Utility again. This time the scan completed successfully.
Did the diagnostic test restart a driver? How do I keep the scanner connected properly.
01-15-2020 09:18 PM
PS: When the scanner is in a working state and I try to initiate a scan using the printer (scan to PC) it will recognise that an original is in the feeder and display a status saying it is scanning but then does nothing. It will hang for a while. I tried canceling the scan and the dialog on the printer screen will go away but then a status message in the lower left of the screen says that it is still scanning. Eventually the printer will beep and this status will go away. After all this I can still initiate a scan successfully from the same PC that is connected via USB.
01-16-2020 06:30 PM
Update: I again had the issue with the MF Scan Utility failing to scan and dissapearing. I tried the go to Devices and Printers and perform the Test Scanner diagnostic as previously. This time the test was successful but MF Scan Utility still did not work after.
01-17-2020 01:45 PM
Hello again JeffBradway.
On the printer, go to Settings Menu > <Preferences> > <Network> <TCP/IP Settings> > <Check Settings>. What link quality is listed for the wifi connection? If it's bad, then something is obstructing the wifi signal; move the printer closer to the router (no closer than ~ 2 ft), minimize obstructions between the printer and router, and/or try removing any new electronics/electrical devices from between the printer and router. Some electronic/electrical devices are not designed with proper shielding, causing them to create interference to wifi and radio signals.
You may also have to check the settings on your access point, router, or modem to ensure the printer and computer are being allowed to communicate without interference from router settings.
If you need immediate assistance with this issue, please contact us using the numbers and information at http://Canon.us/ContactLI
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01-22-2020 02:43 PM
I will check the link strength when I'm back by the printer. However, remember that the trouble I am having occurs over USB connections as well. In fact, my primary way of using this printer is over the USB connection to my desktop PC. Are you saying that WIFI connection issues can cause link problems with the USB?
01-24-2020 01:01 PM
Hi JeffBradway.
If you're using a Windows computer, the wifi and USB will be treated as separate devices. Because of this, the entries for printing or scanning over the wireless network may not be affected by connecting a USB cord.
If the MF644Cdw's separate USB entry in the Printers & Scanners list also is not working, or if this is happening on Mac OS, then you'll also want to check the security software on each respective computer. Ensure the printer's communications are being allowed through; firewalls and antivirus commonly block large-volume unsolicited data from external sources automatically (and, at times, solicited data beyond a certain threshold).
If the computers are laptops, ensure they are plugged in to power; USB signal strength may be too low when the computer is running on battery power.
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06-03-2020 01:49 PM
Did you ever resolve your issue? If so, what did you do? I have the same problem with my MF644 printer and its scanning. I am also using USB Connection and Windows 10. 64 bit on a desktop Dell. Everytime I shut down the computer at night and start the computer in the morning via the start button on the tower, I can't scan and get the same error message you do. But if I restart the computer, then it seems I can scan all day until the computer shuts down again.
06-14-2022 11:07 AM
The Canon software and drivers for the ImageClass MF644Cdw, cannot differentiate when you are using USB or Wi-fi. Even when you select one or the other during installation of the software/drivers, the software will drop BOTH USB and Wi-fi drivers on your Windows machine. When the printer has Wi-fi turned on and the Windows machine is connected to the printer via USB, Windows cannot figure out which to use and then you will get Driver Contention which causes the Communication error/Connection issue. Simply put, you cannot have both Wi-fi turned on in the printer AND have the printer installed on a workstation via USB. Remote computers on your network will print / scan fine but the USB attached computer is going to have all of the issues. Here is what I discovered - that has fixed the issue for me.
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